gdal.h:栅格C API

Public (C callable) GDAL entry points.

定义

INIT_RASTERIO_EXTRA_ARG(s)

Macro to initialize an instance of GDALRasterIOExtraArg structure.

Since

GDAL 2.0

GDALMD_AREA_OR_POINT

Metadata item for dataset that indicates the spatial interpretation of a pixel.

GDALMD_AOP_AREA

Value for GDALMD_AREA_OR_POINT that indicates that a pixel represents an area.

GDALMD_AOP_POINT

Value for GDALMD_AREA_OR_POINT that indicates that a pixel represents a point.

GDAL_DMD_LONGNAME

Long name of the driver.

GDAL_DMD_HELPTOPIC

URL (relative to http://gdal.org/) to the help page of the driver.

GDAL_DMD_MIMETYPE

MIME type handled by the driver.

GDAL_DMD_EXTENSION

Extension handled by the driver.

GDAL_DMD_CONNECTION_PREFIX

Connection prefix to provide as the file name of the open function.

Typically set for non-file based drivers. Generally used with open options.

Since

GDAL 2.0

GDAL_DMD_EXTENSIONS

List of (space separated) extensions handled by the driver.

Since

GDAL 2.0

GDAL_DMD_CREATIONOPTIONLIST

XML snippet with creation options.

GDAL_DMD_MULTIDIM_DATASET_CREATIONOPTIONLIST

XML snippet with multidimensional dataset creation options.

Since

GDAL 3.1

GDAL_DMD_MULTIDIM_GROUP_CREATIONOPTIONLIST

XML snippet with multidimensional group creation options.

Since

GDAL 3.1

GDAL_DMD_MULTIDIM_DIMENSION_CREATIONOPTIONLIST

XML snippet with multidimensional dimension creation options.

Since

GDAL 3.1

GDAL_DMD_MULTIDIM_ARRAY_CREATIONOPTIONLIST

XML snippet with multidimensional array creation options.

Since

GDAL 3.1

GDAL_DMD_MULTIDIM_ATTRIBUTE_CREATIONOPTIONLIST

XML snippet with multidimensional attribute creation options.

Since

GDAL 3.1

GDAL_DMD_OPENOPTIONLIST

XML snippet with open options.

Since

GDAL 2.0

GDAL_DMD_CREATIONDATATYPES

List of (space separated) raster data types support by the Create()/CreateCopy() API.

GDAL_DMD_CREATIONFIELDDATATYPES

List of (space separated) vector field types support by the CreateField() API.

Since

GDAL 2.0

GDAL_DMD_CREATIONFIELDDATASUBTYPES

List of (space separated) vector field sub-types support by the CreateField() API.

Since

GDAL 2.3

GDAL_DMD_SUBDATASETS

Capability set by a driver that exposes Subdatasets.

This capability reflects that a raster driver supports child layers, such as NetCDF or multi-table raster Geopackages.

See GDAL_DCAP_MULTIPLE_VECTOR_LAYERS for a similar capability flag for vector drivers.

GDAL_DCAP_OPEN

Capability set by a driver that implements the Open() API.

GDAL_DCAP_CREATE

Capability set by a driver that implements the Create() API.

If GDAL_DCAP_CREATE is set, but GDAL_DCAP_CREATECOPY not, a generic CreateCopy() implementation is available and will use the Create() API of the driver. So to test if some CreateCopy() implementation is available, generic or specialize, test for both GDAL_DCAP_CREATE and GDAL_DCAP_CREATECOPY.

GDAL_DCAP_CREATE_MULTIDIMENSIONAL

Capability set by a driver that implements the CreateMultidimensional() API.

Since

GDAL 3.1

GDAL_DCAP_CREATECOPY

Capability set by a driver that implements the CreateCopy() API.

If GDAL_DCAP_CREATECOPY is not defined, but GDAL_DCAP_CREATE is set, a generic CreateCopy() implementation is available and will use the Create() API of the driver. So to test if some CreateCopy() implementation is available, generic or specialize, test for both GDAL_DCAP_CREATE and GDAL_DCAP_CREATECOPY.

GDAL_DCAP_CREATECOPY_MULTIDIMENSIONAL

Capability set by a driver that implements the CreateCopy() API, but with multidimensional raster as input and output.

Since

GDAL 3.1

GDAL_DCAP_MULTIDIM_RASTER

Capability set by a driver that supports multidimensional data.

Since

GDAL 3.1

GDAL_DCAP_SUBCREATECOPY

Capability set by a driver that can copy over subdatasets.

GDAL_DCAP_VIRTUALIO

Capability set by a driver that can read/create datasets through the VSI*L API.

GDAL_DCAP_RASTER

Capability set by a driver having raster capability.

Since

GDAL 2.0

GDAL_DCAP_VECTOR

Capability set by a driver having vector capability.

Since

GDAL 2.0

GDAL_DCAP_GNM

Capability set by a driver having geographical network model capability.

Since

GDAL 2.1

GDAL_DCAP_NOTNULL_FIELDS

Capability set by a driver that can create fields with NOT NULL constraint.

Since

GDAL 2.0

GDAL_DCAP_UNIQUE_FIELDS

Capability set by a driver that can create fields with UNIQUE constraint.

Since

GDAL 3.2

GDAL_DCAP_DEFAULT_FIELDS

Capability set by a driver that can create fields with DEFAULT values.

Since

GDAL 2.0

GDAL_DCAP_NOTNULL_GEOMFIELDS

Capability set by a driver that can create geometry fields with NOT NULL constraint.

Since

GDAL 2.0

GDAL_DCAP_NONSPATIAL

Capability set by a non-spatial driver having no support for geometries.

E.g. non-spatial vector drivers (e.g. spreadsheet format drivers) do not support geometries, and accordingly will have this capability present.

Since

GDAL 2.3

GDAL_DCAP_FEATURE_STYLES

Capability set by drivers which support feature styles.

Since

GDAL 2.3

GDAL_DCAP_COORDINATE_EPOCH

Capability set by drivers which support storing/retrieving coordinate epoch for dynamic CRS.

Since

GDAL 3.4

GDAL_DCAP_MULTIPLE_VECTOR_LAYERS

Capability set by drivers for formats which support multiple vector layers.

Note: some GDAL drivers expose "virtual" layer support while the underlying formats themselves do not. This capability is only set for drivers of formats which have a native concept of multiple vector layers (such as GeoPackage).

Since

GDAL 3.4

GDAL_DCAP_FIELD_DOMAINS

Capability set by drivers for formats which support reading field domains.

Since

GDAL 3.5

GDAL_DCAP_RENAME_LAYERS

Capability set by drivers for formats which support renaming vector layers.

Since

GDAL 3.5

GDAL_DMD_CREATION_FIELD_DOMAIN_TYPES

List of (space separated) field domain types support by the AddFieldDomain() API.

Supported values are Coded, Range and Glob, corresponding to the OGRFieldDomainType::OFDT_CODED, OGRFieldDomainType::OFDT_RANGE, and OGRFieldDomainType::OFDT_GLOB field domain types respectively.

Since

GDAL 3.5

GDAL_DIM_TYPE_HORIZONTAL_X

Value for GDALDimension::GetType() specifying the X axis of a horizontal CRS.

Since

GDAL 3.1

GDAL_DIM_TYPE_HORIZONTAL_Y

Value for GDALDimension::GetType() specifying the Y axis of a horizontal CRS.

Since

GDAL 3.1

GDAL_DIM_TYPE_VERTICAL

Value for GDALDimension::GetType() specifying a vertical axis.

Since

GDAL 3.1

GDAL_DIM_TYPE_TEMPORAL

Value for GDALDimension::GetType() specifying a temporal axis.

Since

GDAL 3.1

GDAL_DIM_TYPE_PARAMETRIC

Value for GDALDimension::GetType() specifying a parametric axis.

Since

GDAL 3.1

GDAL_OF_READONLY

Open in read-only mode.

Used by GDALOpenEx().

Since

GDAL 2.0

GDAL_OF_UPDATE

Open in update mode.

Used by GDALOpenEx().

Since

GDAL 2.0

GDAL_OF_ALL

Allow raster and vector drivers to be used.

Used by GDALOpenEx().

Since

GDAL 2.0

GDAL_OF_RASTER

Allow raster drivers to be used.

Used by GDALOpenEx().

Since

GDAL 2.0

GDAL_OF_VECTOR

Allow vector drivers to be used.

Used by GDALOpenEx().

Since

GDAL 2.0

GDAL_OF_GNM

Allow gnm drivers to be used.

Used by GDALOpenEx().

Since

GDAL 2.1

GDAL_OF_MULTIDIM_RASTER

Allow multidimensional raster drivers to be used.

Used by GDALOpenEx().

Since

GDAL 3.1

GDAL_OF_SHARED

Open in shared mode.

Used by GDALOpenEx().

Since

GDAL 2.0

GDAL_OF_VERBOSE_ERROR

Emit error message in case of failed open.

Used by GDALOpenEx().

Since

GDAL 2.0

GDAL_OF_INTERNAL

Open as internal dataset.

Such dataset isn't registered in the global list of opened dataset. Cannot be used with GDAL_OF_SHARED.

Used by GDALOpenEx().

Since

GDAL 2.0

GDAL_OF_DEFAULT_BLOCK_ACCESS

Let GDAL decide if a array-based or hashset-based storage strategy for cached blocks must be used.

GDAL_OF_DEFAULT_BLOCK_ACCESS, GDAL_OF_ARRAY_BLOCK_ACCESS and GDAL_OF_HASHSET_BLOCK_ACCESS are mutually exclusive.

Used by GDALOpenEx().

Since

GDAL 2.1

GDAL_OF_ARRAY_BLOCK_ACCESS

Use a array-based storage strategy for cached blocks.

GDAL_OF_DEFAULT_BLOCK_ACCESS, GDAL_OF_ARRAY_BLOCK_ACCESS and GDAL_OF_HASHSET_BLOCK_ACCESS are mutually exclusive.

Used by GDALOpenEx().

Since

GDAL 2.1

GDAL_OF_HASHSET_BLOCK_ACCESS

Use a hashset-based storage strategy for cached blocks.

GDAL_OF_DEFAULT_BLOCK_ACCESS, GDAL_OF_ARRAY_BLOCK_ACCESS and GDAL_OF_HASHSET_BLOCK_ACCESS are mutually exclusive.

Used by GDALOpenEx().

Since

GDAL 2.1

GDAL_DS_LAYER_CREATIONOPTIONLIST

Name of driver metadata item for layer creation option list.

SRCVAL(papoSource, eSrcType, ii)

SRCVAL - Macro which may be used by pixel functions to obtain a pixel from a source buffer.

GMF_ALL_VALID

Flag returned by GDALGetMaskFlags() to indicate that all pixels are valid.

GMF_PER_DATASET

Flag returned by GDALGetMaskFlags() to indicate that the mask band is valid for all bands.

GMF_ALPHA

Flag returned by GDALGetMaskFlags() to indicate that the mask band is an alpha band.

GMF_NODATA

Flag returned by GDALGetMaskFlags() to indicate that the mask band is computed from nodata values.

GDAL_DATA_COVERAGE_STATUS_UNIMPLEMENTED

Flag returned by GDALGetDataCoverageStatus() when the driver does not implement GetDataCoverageStatus().

This flag should be returned together with GDAL_DATA_COVERAGE_STATUS_DATA

GDAL_DATA_COVERAGE_STATUS_DATA

Flag returned by GDALGetDataCoverageStatus() when there is (potentially) data in the queried window.

Can be combined with the binary or operator with GDAL_DATA_COVERAGE_STATUS_UNIMPLEMENTED or GDAL_DATA_COVERAGE_STATUS_EMPTY

GDAL_DATA_COVERAGE_STATUS_EMPTY

Flag returned by GDALGetDataCoverageStatus() when there is nodata in the queried window.

This is typically identified by the concept of missing block in formats that supports it. Can be combined with the binary or operator with GDAL_DATA_COVERAGE_STATUS_DATA

GDAL_CHECK_VERSION(pszCallingComponentName)

Helper macro for GDALCheckVersion()

参见

GDALCheckVersion()

类型定义

typedef void *GDALMajorObjectH

Opaque type used for the C bindings of the C++ GDALMajorObject class.

typedef void *GDALDatasetH

Opaque type used for the C bindings of the C++ GDALDataset class.

typedef void *GDALRasterBandH

Opaque type used for the C bindings of the C++ GDALRasterBand class.

typedef void *GDALDriverH

Opaque type used for the C bindings of the C++ GDALDriver class.

typedef void *GDALColorTableH

Opaque type used for the C bindings of the C++ GDALColorTable class.

typedef void *GDALRasterAttributeTableH

Opaque type used for the C bindings of the C++ GDALRasterAttributeTable class.

typedef void *GDALAsyncReaderH

Opaque type used for the C bindings of the C++ GDALAsyncReader class.

typedef GIntBig GSpacing

Type to express pixel, line or band spacing.

Signed 64 bit integer.

typedef struct GDALExtendedDataTypeHS *GDALExtendedDataTypeH

Opaque type for C++ GDALExtendedDataType.

typedef struct GDALEDTComponentHS *GDALEDTComponentH

Opaque type for C++ GDALEDTComponent.

typedef struct GDALGroupHS *GDALGroupH

Opaque type for C++ GDALGroup.

typedef struct GDALMDArrayHS *GDALMDArrayH

Opaque type for C++ GDALMDArray.

typedef struct GDALAttributeHS *GDALAttributeH

Opaque type for C++ GDALAttribute.

typedef struct GDALDimensionHS *GDALDimensionH

Opaque type for C++ GDALDimension.

typedef CPLErr (*GDALDerivedPixelFunc)(void **papoSources, int nSources, void *pData, int nBufXSize, int nBufYSize, GDALDataType eSrcType, GDALDataType eBufType, int nPixelSpace, int nLineSpace)

Type of functions to pass to GDALAddDerivedBandPixelFunc.

Since

GDAL 2.2

typedef CPLErr (*GDALDerivedPixelFuncWithArgs)(void **papoSources, int nSources, void *pData, int nBufXSize, int nBufYSize, GDALDataType eSrcType, GDALDataType eBufType, int nPixelSpace, int nLineSpace, CSLConstList papszFunctionArgs)

Type of functions to pass to GDALAddDerivedBandPixelFuncWithArgs.

Since

GDAL 3.4

枚举类型

enum GDALDataType

Pixel data types

Values:

enumerator GDT_Unknown

Unknown or unspecified type

enumerator GDT_Byte

Eight bit unsigned integer

enumerator GDT_UInt16

Sixteen bit unsigned integer

enumerator GDT_Int16

Sixteen bit signed integer

enumerator GDT_UInt32

Thirty two bit unsigned integer

enumerator GDT_Int32

Thirty two bit signed integer

enumerator GDT_UInt64

64 bit unsigned integer (GDAL >= 3.5)

enumerator GDT_Int64

64 bit signed integer (GDAL >= 3.5)

enumerator GDT_Float32

Thirty two bit floating point

enumerator GDT_Float64

Sixty four bit floating point

enumerator GDT_CInt16

Complex Int16

enumerator GDT_CInt32

Complex Int32

enumerator GDT_CFloat32

Complex Float32

enumerator GDT_CFloat64

Complex Float64

enumerator GDT_TypeCount

enum GDALAsyncStatusType

status of the asynchronous stream

Values:

enumerator GARIO_PENDING

enumerator GARIO_UPDATE

enumerator GARIO_ERROR

enumerator GARIO_COMPLETE

enumerator GARIO_TypeCount

enum GDALAccess

Flag indicating read/write, or read-only access to data.

Values:

enumerator GA_ReadOnly

Read only (no update) access

enumerator GA_Update

Read/write access.

enum GDALRWFlag

Read/Write flag for RasterIO() method

Values:

enumerator GF_Read

Read data

enumerator GF_Write

Write data

enum GDALRIOResampleAlg

RasterIO() resampling method.

Since

GDAL 2.0

Values:

enumerator GRIORA_NearestNeighbour

Nearest neighbour

enumerator GRIORA_Bilinear

Bilinear (2x2 kernel)

enumerator GRIORA_Cubic

Cubic Convolution Approximation (4x4 kernel)

enumerator GRIORA_CubicSpline

Cubic B-Spline Approximation (4x4 kernel)

enumerator GRIORA_Lanczos

Lanczos windowed sinc interpolation (6x6 kernel)

enumerator GRIORA_Average

Average

enumerator GRIORA_Mode

Mode (selects the value which appears most often of all the sampled points)

enumerator GRIORA_Gauss

Gauss blurring

enumerator GRIORA_RMS

RMS: Root Mean Square / Quadratic Mean.

For complex numbers, applies on the real and imaginary part independently.

enum GDALColorInterp

Types of color interpretation for raster bands.

Values:

enumerator GCI_Undefined

Undefined

enumerator GCI_GrayIndex

Greyscale

enumerator GCI_PaletteIndex

Paletted (see associated color table)

enumerator GCI_RedBand

Red band of RGBA image

enumerator GCI_GreenBand

Green band of RGBA image

enumerator GCI_BlueBand

Blue band of RGBA image

enumerator GCI_AlphaBand

Alpha (0=transparent, 255=opaque)

enumerator GCI_HueBand

Hue band of HLS image

enumerator GCI_SaturationBand

Saturation band of HLS image

enumerator GCI_LightnessBand

Lightness band of HLS image

enumerator GCI_CyanBand

Cyan band of CMYK image

enumerator GCI_MagentaBand

Magenta band of CMYK image

enumerator GCI_YellowBand

Yellow band of CMYK image

enumerator GCI_BlackBand

Black band of CMYK image

enumerator GCI_YCbCr_YBand

Y Luminance

enumerator GCI_YCbCr_CbBand

Cb Chroma

enumerator GCI_YCbCr_CrBand

Cr Chroma

enumerator GCI_Max

Max current value (equals to GCI_YCbCr_CrBand currently)

enum GDALPaletteInterp

Types of color interpretations for a GDALColorTable.

Values:

enumerator GPI_Gray

Grayscale (in GDALColorEntry.c1)

enumerator GPI_RGB

Red, Green, Blue and Alpha in (in c1, c2, c3 and c4)

enumerator GPI_CMYK

Cyan, Magenta, Yellow and Black (in c1, c2, c3 and c4)

enumerator GPI_HLS

Hue, Lightness and Saturation (in c1, c2, and c3)

enum GDALExtendedDataTypeClass

Enumeration giving the class of a GDALExtendedDataType.

Since

GDAL 3.1

Values:

enumerator GEDTC_NUMERIC

Numeric value.

Based on GDALDataType enumeration

enumerator GEDTC_STRING

String value.

enumerator GEDTC_COMPOUND

Compound data type.

enum GDALExtendedDataTypeSubType

Enumeration giving the subtype of a GDALExtendedDataType.

Since

GDAL 3.4

Values:

enumerator GEDTST_NONE

None.

enumerator GEDTST_JSON

JSon.

Only applies to GEDTC_STRING

enum GDALRATFieldType

Field type of raster attribute table.

Values:

enumerator GFT_Integer

Integer field

enumerator GFT_Real

Floating point (double) field

enumerator GFT_String

String field

enum GDALRATFieldUsage

Field usage of raster attribute table.

Values:

enumerator GFU_Generic

General purpose field.

enumerator GFU_PixelCount

Histogram pixel count

enumerator GFU_Name

Class name

enumerator GFU_Min

Class range minimum

enumerator GFU_Max

Class range maximum

enumerator GFU_MinMax

Class value (min=max)

enumerator GFU_Red

Red class color (0-255)

enumerator GFU_Green

Green class color (0-255)

enumerator GFU_Blue

Blue class color (0-255)

enumerator GFU_Alpha

Alpha (0=transparent,255=opaque)

enumerator GFU_RedMin

Color Range Red Minimum

enumerator GFU_GreenMin

Color Range Green Minimum

enumerator GFU_BlueMin

Color Range Blue Minimum

enumerator GFU_AlphaMin

Color Range Alpha Minimum

enumerator GFU_RedMax

Color Range Red Maximum

enumerator GFU_GreenMax

Color Range Green Maximum

enumerator GFU_BlueMax

Color Range Blue Maximum

enumerator GFU_AlphaMax

Color Range Alpha Maximum

enumerator GFU_MaxCount

Maximum GFU value (equals to GFU_AlphaMax+1 currently)

enum GDALRATTableType

RAT table type (thematic or athematic)

Since

GDAL 2.4

Values:

enumerator GRTT_THEMATIC

Thematic table type

enumerator GRTT_ATHEMATIC

Athematic table type

enum GDALTileOrganization

! Enumeration to describe the tile organization

Values:

enumerator GTO_TIP

Tile Interleaved by Pixel: tile (0,0) with internal band interleaved by pixel organization, tile (1, 0), ...

enumerator GTO_BIT

Band Interleaved by Tile : tile (0,0) of first band, tile (0,0) of second band, ... tile (1,0) of first band, tile (1,0) of second band, ...

enumerator GTO_BSQ

Band SeQuential : all the tiles of first band, all the tiles of following band...

功能

int GDALGetDataTypeSize(GDALDataType)

Get data type size in bits.

Deprecated.

Returns the size of a GDT_* type in bits, not bytes!

Use GDALGetDataTypeSizeBytes() for bytes. Use GDALGetDataTypeSizeBits() for bits.

参数

eDataType -- type, such as GDT_Byte.

返回

the number of bits or zero if it is not recognised.

int GDALGetDataTypeSizeBits(GDALDataType eDataType)

Get data type size in bits.

Returns the size of a GDT_* type in bits, not bytes! Use GDALGetDataTypeSizeBytes() for bytes.

参数

eDataType -- type, such as GDT_Byte.

返回

the number of bits or zero if it is not recognised.

int GDALGetDataTypeSizeBytes(GDALDataType)

Get data type size in bytes.

Returns the size of a GDT_* type in bytes. In contrast, GDALGetDataTypeSize() returns the size in bits.

参数

eDataType -- type, such as GDT_Byte.

返回

the number of bytes or zero if it is not recognised.

int GDALDataTypeIsComplex(GDALDataType)

Is data type complex?

返回

TRUE if the passed type is complex (one of GDT_CInt16, GDT_CInt32, GDT_CFloat32 or GDT_CFloat64), that is it consists of a real and imaginary component.

int GDALDataTypeIsInteger(GDALDataType)

Is data type integer? (might be complex)

Since

GDAL 2.3

返回

TRUE if the passed type is integer (one of GDT_Byte, GDT_Int16, GDT_UInt16, GDT_Int32, GDT_UInt32, GDT_CInt16, GDT_CInt32).

int GDALDataTypeIsFloating(GDALDataType)

Is data type floating? (might be complex)

Since

GDAL 2.3

返回

TRUE if the passed type is floating (one of GDT_Float32, GDT_Float64, GDT_CFloat32, GDT_CFloat64)

int GDALDataTypeIsSigned(GDALDataType)

Is data type signed?

Since

GDAL 2.3

返回

TRUE if the passed type is signed.

const char *GDALGetDataTypeName(GDALDataType)

Get name of data type.

Returns a symbolic name for the data type. This is essentially the the enumerated item name with the GDT_ prefix removed. So GDT_Byte returns "Byte". The returned strings are static strings and should not be modified or freed by the application. These strings are useful for reporting datatypes in debug statements, errors and other user output.

参数

eDataType -- type to get name of.

返回

string corresponding to existing data type or NULL pointer if invalid type given.

GDALDataType GDALGetDataTypeByName(const char*)

Get data type by symbolic name.

Returns a data type corresponding to the given symbolic name. This function is opposite to the GDALGetDataTypeName().

参数

pszName -- string containing the symbolic name of the type.

返回

GDAL data type.

GDALDataType GDALDataTypeUnion(GDALDataType, GDALDataType)

Return the smallest data type that can fully express both input data types.

参数

• eType1 -- first data type.

• eType2 -- second data type.

返回

a data type able to express eType1 and eType2.

GDALDataType GDALDataTypeUnionWithValue(GDALDataType eDT, double dValue, int bComplex)

Union a data type with the one found for a value.

Since

GDAL 2.3

参数

• eDT -- the first data type

• dValue -- the value for which to find a data type and union with eDT

• bComplex -- if the value is complex

返回

a data type able to express eDT and dValue.

GDALDataType GDALFindDataType(int nBits, int bSigned, int bFloating, int bComplex)

Finds the smallest data type able to support the given requirements.

Since

GDAL 2.3

参数

• nBits -- number of bits necessary

• bSigned -- if negative values are necessary

• bFloating -- if non-integer values necessary

• bComplex -- if complex values are necessary

返回

a best fit GDALDataType for supporting the requirements

GDALDataType GDALFindDataTypeForValue(double dValue, int bComplex)

Finds the smallest data type able to support the provided value.

Since

GDAL 2.3

参数

• dValue -- value to support

• bComplex -- is the value complex

返回

a best fit GDALDataType for supporting the value

double GDALAdjustValueToDataType(GDALDataType eDT, double dfValue, int *pbClamped, int *pbRounded)

Adjust a value to the output data type.

Adjustment consist in clamping to minimum/maximum values of the data type and rounding for integral types.

Since

GDAL 2.1

参数

• eDT -- target data type.

• dfValue -- value to adjust.

• pbClamped -- pointer to a integer(boolean) to indicate if clamping has been made, or NULL

• pbRounded -- pointer to a integer(boolean) to indicate if rounding has been made, or NULL

返回

adjusted value

GDALDataType GDALGetNonComplexDataType(GDALDataType)

Return the base data type for the specified input.

If the input data type is complex this function returns the base type i.e. the data type of the real and imaginary parts (non-complex). If the input data type is already non-complex, then it is returned unchanged.

参数

eDataType -- type, such as GDT_CFloat32.

返回

GDAL data type.

int GDALDataTypeIsConversionLossy(GDALDataType eTypeFrom, GDALDataType eTypeTo)

Is conversion from eTypeFrom to eTypeTo potentially lossy.

Since

GDAL 2.3

参数

• eTypeFrom -- input datatype

• eTypeTo -- output datatype

返回

TRUE if conversion from eTypeFrom to eTypeTo potentially lossy.

const char *GDALGetAsyncStatusTypeName(GDALAsyncStatusType)

Get name of AsyncStatus data type.

Returns a symbolic name for the AsyncStatus data type. This is essentially the the enumerated item name with the GARIO_ prefix removed. So GARIO_COMPLETE returns "COMPLETE". The returned strings are static strings and should not be modified or freed by the application. These strings are useful for reporting datatypes in debug statements, errors and other user output.

参数

eAsyncStatusType -- type to get name of.

返回

string corresponding to type.

GDALAsyncStatusType GDALGetAsyncStatusTypeByName(const char*)

Get AsyncStatusType by symbolic name.

Returns a data type corresponding to the given symbolic name. This function is opposite to the GDALGetAsyncStatusTypeName().

参数

pszName -- string containing the symbolic name of the type.

返回

GDAL AsyncStatus type.

const char *GDALGetColorInterpretationName(GDALColorInterp)

Get name of color interpretation.

Returns a symbolic name for the color interpretation. This is derived from the enumerated item name with the GCI_ prefix removed, but there are some variations. So GCI_GrayIndex returns "Gray" and GCI_RedBand returns "Red". The returned strings are static strings and should not be modified or freed by the application.

参数

eInterp -- color interpretation to get name of.

返回

string corresponding to color interpretation or NULL pointer if invalid enumerator given.

GDALColorInterp GDALGetColorInterpretationByName(const char *pszName)

Get color interpretation by symbolic name.

Returns a color interpretation corresponding to the given symbolic name. This function is opposite to the GDALGetColorInterpretationName().

Since

GDAL 1.7.0

参数

pszName -- string containing the symbolic name of the color interpretation.

返回

GDAL color interpretation.

const char *GDALGetPaletteInterpretationName(GDALPaletteInterp)

Get name of palette interpretation.

Returns a symbolic name for the palette interpretation. This is the the enumerated item name with the GPI_ prefix removed. So GPI_Gray returns "Gray". The returned strings are static strings and should not be modified or freed by the application.

参数

eInterp -- palette interpretation to get name of.

返回

string corresponding to palette interpretation.

void GDALAllRegister(void)

Register all known configured GDAL drivers.

This function will drive any of the following that are configured into GDAL. See raster list and vector full list

This function should generally be called once at the beginning of the application.

GDALDatasetH GDALCreate(GDALDriverH hDriver, const char*, int, int, int, GDALDataType, CSLConstList)

Create a new dataset with this driver.

参见

GDALDriver::Create()

GDALDatasetH GDALCreateCopy(GDALDriverH, const char*, GDALDatasetH, int, CSLConstList, GDALProgressFunc, void*)

Create a copy of a dataset.

参见

GDALDriver::CreateCopy()

GDALDriverH GDALIdentifyDriver(const char *pszFilename, CSLConstList papszFileList)

Identify the driver that can open a raster file.

This function will try to identify the driver that can open the passed file name by invoking the Identify method of each registered GDALDriver in turn. The first driver that successful identifies the file name will be returned. If all drivers fail then NULL is returned.

In order to reduce the need for such searches touch the operating system file system machinery, it is possible to give an optional list of files. This is the list of all files at the same level in the file system as the target file, including the target file. The filenames will not include any path components, are essentially just the output of VSIReadDir() on the parent directory. If the target object does not have filesystem semantics then the file list should be NULL.

参数

• pszFilename -- the name of the file to access. In the case of exotic drivers this may not refer to a physical file, but instead contain information for the driver on how to access a dataset.

• papszFileList -- an array of strings, whose last element is the NULL pointer. These strings are filenames that are auxiliary to the main filename. The passed value may be NULL.

返回

A GDALDriverH handle or NULL on failure. For C++ applications this handle can be cast to a GDALDriver *.

GDALDriverH GDALIdentifyDriverEx(const char *pszFilename, unsigned int nIdentifyFlags, const char *const *papszAllowedDrivers, const char *const *papszFileList)

Identify the driver that can open a raster file.

This function will try to identify the driver that can open the passed file name by invoking the Identify method of each registered GDALDriver in turn. The first driver that successful identifies the file name will be returned. If all drivers fail then NULL is returned.

In order to reduce the need for such searches touch the operating system file system machinery, it is possible to give an optional list of files. This is the list of all files at the same level in the file system as the target file, including the target file. The filenames will not include any path components, are essentially just the output of VSIReadDir() on the parent directory. If the target object does not have filesystem semantics then the file list should be NULL.

Since

GDAL 2.2

参数

• pszFilename -- the name of the file to access. In the case of exotic drivers this may not refer to a physical file, but instead contain information for the driver on how to access a dataset.

• nIdentifyFlags -- a combination of GDAL_OF_RASTER for raster drivers or GDAL_OF_VECTOR for vector drivers. If none of the value is specified, both kinds are implied.

• papszAllowedDrivers -- NULL to consider all candidate drivers, or a NULL terminated list of strings with the driver short names that must be considered.

• papszFileList -- an array of strings, whose last element is the NULL pointer. These strings are filenames that are auxiliary to the main filename. The passed value may be NULL.

返回

A GDALDriverH handle or NULL on failure. For C++ applications this handle can be cast to a GDALDriver *.

GDALDatasetH GDALOpen(const char *pszFilename, GDALAccess eAccess)

Open a raster file as a GDALDataset.

This function will try to open the passed file, or virtual dataset name by invoking the Open method of each registered GDALDriver in turn. The first successful open will result in a returned dataset. If all drivers fail then NULL is returned and an error is issued.

Several recommendations :

• If you open a dataset object with GA_Update access, it is not recommended to open a new dataset on the same underlying file.

• The returned dataset should only be accessed by one thread at a time. If you want to use it from different threads, you must add all necessary code (mutexes, etc.) to avoid concurrent use of the object. (Some drivers, such as GeoTIFF, maintain internal state variables that are updated each time a new block is read, thus preventing concurrent use.)

For drivers supporting the VSI virtual file API, it is possible to open a file in a .zip archive (see VSIInstallZipFileHandler()), in a .tar/.tar.gz/.tgz archive (see VSIInstallTarFileHandler()) or on a HTTP / FTP server (see VSIInstallCurlFileHandler())

参见

GDALOpenShared()

参见

GDALOpenEx()

参数

• pszFilename -- the name of the file to access. In the case of exotic drivers this may not refer to a physical file, but instead contain information for the driver on how to access a dataset. It should be in UTF-8 encoding.

• eAccess -- the desired access, either GA_Update or GA_ReadOnly. Many drivers support only read only access.

返回

A GDALDatasetH handle or NULL on failure. For C++ applications this handle can be cast to a GDALDataset *.

GDALDatasetH GDALOpenShared(const char*, GDALAccess)

Open a raster file as a GDALDataset.

This function works the same as GDALOpen(), but allows the sharing of GDALDataset handles for a dataset with other callers to GDALOpenShared().

In particular, GDALOpenShared() will first consult its list of currently open and shared GDALDataset's, and if the GetDescription() name for one exactly matches the pszFilename passed to GDALOpenShared() it will be referenced and returned.

Starting with GDAL 1.6.0, if GDALOpenShared() is called on the same pszFilename from two different threads, a different GDALDataset object will be returned as it is not safe to use the same dataset from different threads, unless the user does explicitly use mutexes in its code.

For drivers supporting the VSI virtual file API, it is possible to open a file in a .zip archive (see VSIInstallZipFileHandler()), in a .tar/.tar.gz/.tgz archive (see VSIInstallTarFileHandler()) or on a HTTP / FTP server (see VSIInstallCurlFileHandler())

参见

GDALOpen()

参见

GDALOpenEx()

参数

• pszFilename -- the name of the file to access. In the case of exotic drivers this may not refer to a physical file, but instead contain information for the driver on how to access a dataset. It should be in UTF-8 encoding.

• eAccess -- the desired access, either GA_Update or GA_ReadOnly. Many drivers support only read only access.

返回

A GDALDatasetH handle or NULL on failure. For C++ applications this handle can be cast to a GDALDataset *.

GDALDatasetH GDALOpenEx(const char *pszFilename, unsigned int nOpenFlags, const char *const *papszAllowedDrivers, const char *const *papszOpenOptions, const char *const *papszSiblingFiles)

Open a raster or vector file as a GDALDataset.

This function will try to open the passed file, or virtual dataset name by invoking the Open method of each registered GDALDriver in turn. The first successful open will result in a returned dataset. If all drivers fail then NULL is returned and an error is issued.

Several recommendations :

• If you open a dataset object with GDAL_OF_UPDATE access, it is not recommended to open a new dataset on the same underlying file.

• The returned dataset should only be accessed by one thread at a time. If you want to use it from different threads, you must add all necessary code (mutexes, etc.) to avoid concurrent use of the object. (Some drivers, such as GeoTIFF, maintain internal state variables that are updated each time a new block is read, thus preventing concurrent use.)

For drivers supporting the VSI virtual file API, it is possible to open a file in a .zip archive (see VSIInstallZipFileHandler()), in a .tar/.tar.gz/.tgz archive (see VSIInstallTarFileHandler()) or on a HTTP / FTP server (see VSIInstallCurlFileHandler())

In order to reduce the need for searches through the operating system file system machinery, it is possible to give an optional list of files with the papszSiblingFiles parameter. This is the list of all files at the same level in the file system as the target file, including the target file. The filenames must not include any path components, are essentially just the output of VSIReadDir() on the parent directory. If the target object does not have filesystem semantics then the file list should be NULL.

Since

GDAL 2.0

参数

• pszFilename -- the name of the file to access. In the case of exotic drivers this may not refer to a physical file, but instead contain information for the driver on how to access a dataset. It should be in UTF-8 encoding.

• nOpenFlags -- a combination of GDAL_OF_ flags that may be combined through logical or operator.

  • Driver kind:

    • GDAL_OF_RASTER for raster drivers,

    • GDAL_OF_MULTIDIM_RASTER for multidimensional raster drivers,

    • GDAL_OF_VECTOR for vector drivers,

    • GDAL_OF_GNM for Geographic Network Model drivers.

    GDAL_OF_RASTER and GDAL_OF_MULTIDIM_RASTER are generally mutually exclusive. If none of the value is specified, GDAL_OF_RASTER | GDAL_OF_VECTOR | GDAL_OF_GNM is implied.

  • Access mode: GDAL_OF_READONLY (exclusive)or GDAL_OF_UPDATE.

  • Shared mode: GDAL_OF_SHARED. If set, it allows the sharing of GDALDataset handles for a dataset with other callers that have set GDAL_OF_SHARED. In particular, GDALOpenEx() will first consult its list of currently open and shared GDALDataset's, and if the GetDescription() name for one exactly matches the pszFilename passed to GDALOpenEx() it will be referenced and returned, if GDALOpenEx() is called from the same thread.

  • Verbose error: GDAL_OF_VERBOSE_ERROR. If set, a failed attempt to open the file will lead to an error message to be reported.

• papszAllowedDrivers -- NULL to consider all candidate drivers, or a NULL terminated list of strings with the driver short names that must be considered.

• papszOpenOptions -- NULL, or a NULL terminated list of strings with open options passed to candidate drivers. An option exists for all drivers, OVERVIEW_LEVEL=level, to select a particular overview level of a dataset. The level index starts at 0. The level number can be suffixed by "only" to specify that only this overview level must be visible, and not sub-levels. Open options are validated by default, and a warning is emitted in case the option is not recognized. In some scenarios, it might be not desirable (e.g. when not knowing which driver will open the file), so the special open option VALIDATE_OPEN_OPTIONS can be set to NO to avoid such warnings. Alternatively, since GDAL 2.1, an option name can be preceded by the @ character to indicate that it may not cause a warning if the driver doesn't declare this option. Starting with GDAL 3.3, OVERVIEW_LEVEL=NONE is supported to indicate that no overviews should be exposed.

• papszSiblingFiles -- NULL, or a NULL terminated list of strings that are filenames that are auxiliary to the main filename. If NULL is passed, a probing of the file system will be done.

返回

A GDALDatasetH handle or NULL on failure. For C++ applications this handle can be cast to a GDALDataset *.

int GDALDumpOpenDatasets(FILE*)

List open datasets.

Dumps a list of all open datasets (shared or not) to the indicated text file (may be stdout or stderr). This function is primarily intended to assist in debugging "dataset leaks" and reference counting issues. The information reported includes the dataset name, referenced count, shared status, driver name, size, and band count.

GDALDriverH GDALGetDriverByName(const char*)

Fetch a driver based on the short name.

参见

GDALDriverManager::GetDriverByName()

int GDALGetDriverCount(void)

Fetch the number of registered drivers.

参见

GDALDriverManager::GetDriverCount()

GDALDriverH GDALGetDriver(int)

Fetch driver by index.

参见

GDALDriverManager::GetDriver()

GDALDriverH GDALCreateDriver(void)

Create a GDALDriver.

Creates a driver in the GDAL heap.

void GDALDestroyDriver(GDALDriverH)

Destroy a GDALDriver.

This is roughly equivalent to deleting the driver, but is guaranteed to take place in the GDAL heap. It is important this that function not be called on a driver that is registered with the GDALDriverManager.

参数

hDriver -- the driver to destroy.

int GDALRegisterDriver(GDALDriverH)

Register a driver for use.

参见

GDALDriverManager::GetRegisterDriver()

void GDALDeregisterDriver(GDALDriverH)

Deregister the passed driver.

参见

GDALDriverManager::GetDeregisterDriver()

void GDALDestroyDriverManager(void)

Destroy the driver manager.

Incidentally unloads all managed drivers.

NOTE: This function is not thread safe. It should not be called while other threads are actively using GDAL.

CPLErr GDALDeleteDataset(GDALDriverH, const char*)

Delete named dataset.

参见

GDALDriver::Delete()

CPLErr GDALRenameDataset(GDALDriverH, const char *pszNewName, const char *pszOldName)

Rename a dataset.

参见

GDALDriver::Rename()

CPLErr GDALCopyDatasetFiles(GDALDriverH, const char *pszNewName, const char *pszOldName)

Copy the files of a dataset.

参见

GDALDriver::CopyFiles()

int GDALValidateCreationOptions(GDALDriverH, CSLConstList papszCreationOptions)

Validate the list of creation options that are handled by a driver.

This is a helper method primarily used by Create() and CreateCopy() to validate that the passed in list of creation options is compatible with the GDAL_DMD_CREATIONOPTIONLIST metadata item defined by some drivers.

If the GDAL_DMD_CREATIONOPTIONLIST metadata item is not defined, this function will return TRUE. Otherwise it will check that the keys and values in the list of creation options are compatible with the capabilities declared by the GDAL_DMD_CREATIONOPTIONLIST metadata item. In case of incompatibility a (non fatal) warning will be emitted and FALSE will be returned.

参见

GDALGetDriverCreationOptionList()

参数

• hDriver -- the handle of the driver with whom the lists of creation option must be validated

• papszCreationOptions -- the list of creation options. An array of strings, whose last element is a NULL pointer

返回

TRUE if the list of creation options is compatible with the Create() and CreateCopy() method of the driver, FALSE otherwise.

const char *GDALGetDriverShortName(GDALDriverH)

Return the short name of a driver.

This is the string that can be passed to the GDALGetDriverByName() function.

For the GeoTIFF driver, this is "GTiff"

参数

hDriver -- the handle of the driver

返回

the short name of the driver. The returned string should not be freed and is owned by the driver.

const char *GDALGetDriverLongName(GDALDriverH)

Return the long name of a driver.

For the GeoTIFF driver, this is "GeoTIFF"

参数

hDriver -- the handle of the driver

返回

the long name of the driver or empty string. The returned string should not be freed and is owned by the driver.

const char *GDALGetDriverHelpTopic(GDALDriverH)

Return the URL to the help that describes the driver.

That URL is relative to the GDAL documentation directory.

For the GeoTIFF driver, this is "frmt_gtiff.html"

参数

hDriver -- the handle of the driver

返回

the URL to the help that describes the driver or NULL. The returned string should not be freed and is owned by the driver.

const char *GDALGetDriverCreationOptionList(GDALDriverH)

Return the list of creation options of the driver.

Return the list of creation options of the driver used by Create() and CreateCopy() as an XML string

参数

hDriver -- the handle of the driver

返回

an XML string that describes the list of creation options or empty string. The returned string should not be freed and is owned by the driver.

void GDALInitGCPs(int, GDAL_GCP*)

Initialize an array of GCPs.

Numeric values are initialized to 0 and strings to the empty string "" allocated with CPLStrdup() An array initialized with GDALInitGCPs() must be de-initialized with GDALDeinitGCPs().

参数

• nCount -- number of GCPs in psGCP

• psGCP -- array of GCPs of size nCount.

void GDALDeinitGCPs(int, GDAL_GCP*)

De-initialize an array of GCPs (initialized with GDALInitGCPs())

参数

• nCount -- number of GCPs in psGCP

• psGCP -- array of GCPs of size nCount.

GDAL_GCP *GDALDuplicateGCPs(int, const GDAL_GCP*)

Duplicate an array of GCPs.

The return must be freed with GDALDeinitGCPs() followed by CPLFree()

参数

• nCount -- number of GCPs in psGCP

• pasGCPList -- array of GCPs of size nCount.

int GDALGCPsToGeoTransform(int nGCPCount, const GDAL_GCP *pasGCPs, double *padfGeoTransform, int bApproxOK)

Generate Geotransform from GCPs.

Given a set of GCPs perform first order fit as a geotransform.

Due to imprecision in the calculations the fit algorithm will often return non-zero rotational coefficients even if given perfectly non-rotated inputs. A special case has been implemented for corner corner coordinates given in TL, TR, BR, BL order. So when using this to get a geotransform from 4 corner coordinates, pass them in this order.

Starting with GDAL 2.2.2, if bApproxOK = FALSE, the GDAL_GCPS_TO_GEOTRANSFORM_APPROX_OK configuration option will be read. If set to YES, then bApproxOK will be overridden with TRUE. Starting with GDAL 2.2.2, when exact fit is asked, the GDAL_GCPS_TO_GEOTRANSFORM_APPROX_THRESHOLD configuration option can be set to give the maximum error threshold in pixel. The default is 0.25.

参数

• nGCPCount -- the number of GCPs being passed in.

• pasGCPs -- the list of GCP structures.

• padfGeoTransform -- the six double array in which the affine geotransformation will be returned.

• bApproxOK -- If FALSE the function will fail if the geotransform is not essentially an exact fit (within 0.25 pixel) for all GCPs.

返回

TRUE on success or FALSE if there aren't enough points to prepare a geotransform, the pointers are ill-determined or if bApproxOK is FALSE and the fit is poor.

int GDALInvGeoTransform(double *padfGeoTransformIn, double *padfInvGeoTransformOut)

Invert Geotransform.

This function will invert a standard 3x2 set of GeoTransform coefficients. This converts the equation from being pixel to geo to being geo to pixel.

参数

• gt_in -- Input geotransform (six doubles - unaltered).

• gt_out -- Output geotransform (six doubles - updated).

返回

TRUE on success or FALSE if the equation is uninvertable.

void GDALApplyGeoTransform(double*, double, double, double*, double*)

Apply GeoTransform to x/y coordinate.

Applies the following computation, converting a (pixel, line) coordinate into a georeferenced (geo_x, geo_y) location.

*pdfGeoX = padfGeoTransform[0] + dfPixel * padfGeoTransform[1]
                               + dfLine  * padfGeoTransform[2];
*pdfGeoY = padfGeoTransform[3] + dfPixel * padfGeoTransform[4]
                               + dfLine  * padfGeoTransform[5];

参数

• padfGeoTransform -- Six coefficient GeoTransform to apply.

• dfPixel -- Input pixel position.

• dfLine -- Input line position.

• pdfGeoX -- output location where geo_x (easting/longitude) location is placed.

• pdfGeoY -- output location where geo_y (northing/latitude) location is placed.

void GDALComposeGeoTransforms(const double *padfGeoTransform1, const double *padfGeoTransform2, double *padfGeoTransformOut)

Compose two geotransforms.

The resulting geotransform is the equivalent to padfGT1 and then padfGT2 being applied to a point.

参数

• padfGT1 -- the first geotransform, six values.

• padfGT2 -- the second geotransform, six values.

• padfGTOut -- the output geotransform, six values, may safely be the same array as padfGT1 or padfGT2.

char **GDALGetMetadataDomainList(GDALMajorObjectH hObject)

Fetch list of metadata domains.

参见

GDALMajorObject::GetMetadataDomainList()

Since

GDAL 1.11

char **GDALGetMetadata(GDALMajorObjectH, const char*)

Fetch metadata.

参见

GDALMajorObject::GetMetadata()

CPLErr GDALSetMetadata(GDALMajorObjectH, CSLConstList, const char*)

Set metadata.

CAUTION: when using this function on a GDALDatasetH or GDALRasterBandH, depending on the format, older values of the updated information might still be found in the file in a "ghost" state, even if no longer accessible through the GDAL API. This is for example the case of the GTiff format (this is not a exhaustive list)

参见

GDALMajorObject::SetMetadata(), GDALDataset::SetMetadata(), GDALRasterBand::SetMetadata()

const char *GDALGetMetadataItem(GDALMajorObjectH, const char*, const char*)

Fetch single metadata item.

参见

GDALMajorObject::GetMetadataItem()

CPLErr GDALSetMetadataItem(GDALMajorObjectH, const char*, const char*, const char*)

Set single metadata item.

CAUTION: when using this function on a GDALDatasetH or GDALRasterBandH, depending on the format, older values of the updated information might still be found in the file in a "ghost" state, even if no longer accessible through the GDAL API. This is for example the case of the GTiff format (this is not a exhaustive list)

参见

GDALMajorObject::SetMetadataItem(), GDALDataset::SetMetadataItem(), GDALRasterBand::SetMetadataItem()

const char *GDALGetDescription(GDALMajorObjectH)

Fetch object description.

参见

GDALMajorObject::GetDescription()

void GDALSetDescription(GDALMajorObjectH, const char*)

Set object description.

参见

GDALMajorObject::SetDescription()

GDALDriverH GDALGetDatasetDriver(GDALDatasetH)

Fetch the driver to which this dataset relates.

参见

GDALDataset::GetDriver()

char **GDALGetFileList(GDALDatasetH)

Fetch files forming dataset.

参见

GDALDataset::GetFileList()

void GDALClose(GDALDatasetH)

Close GDAL dataset.

For non-shared datasets (opened with GDALOpen()) the dataset is closed using the C++ "delete" operator, recovering all dataset related resources. For shared datasets (opened with GDALOpenShared()) the dataset is dereferenced, and closed only if the referenced count has dropped below 1.

参数

hDS -- The dataset to close. May be cast from a "GDALDataset *".

int GDALGetRasterXSize(GDALDatasetH)

Fetch raster width in pixels.

参见

GDALDataset::GetRasterXSize().

int GDALGetRasterYSize(GDALDatasetH)

Fetch raster height in pixels.

参见

GDALDataset::GetRasterYSize().

int GDALGetRasterCount(GDALDatasetH)

Fetch the number of raster bands on this dataset.

参见

GDALDataset::GetRasterCount().

GDALRasterBandH GDALGetRasterBand(GDALDatasetH, int)

Fetch a band object for a dataset.

参见

GDALDataset::GetRasterBand().

CPLErr GDALAddBand(GDALDatasetH hDS, GDALDataType eType, CSLConstList papszOptions)

Add a band to a dataset.

参见

GDALDataset::AddBand().

GDALAsyncReaderH GDALBeginAsyncReader(GDALDatasetH hDS, int nXOff, int nYOff, int nXSize, int nYSize, void *pBuf, int nBufXSize, int nBufYSize, GDALDataType eBufType, int nBandCount, int *panBandMap, int nPixelSpace, int nLineSpace, int nBandSpace, CSLConstList papszOptions)

Sets up an asynchronous data request.

This method establish an asynchronous raster read request for the indicated window on the dataset into the indicated buffer. The parameters for windowing, buffer size, buffer type and buffer organization are similar to those for GDALDataset::RasterIO(); however, this call only launches the request and filling the buffer is accomplished via calls to GetNextUpdatedRegion() on the return GDALAsyncReader session object.

Once all processing for the created session is complete, or if no further refinement of the request is required, the GDALAsyncReader object should be destroyed with the GDALDataset::EndAsyncReader() method.

Note that the data buffer (pData) will potentially continue to be updated as long as the session lives, but it is not deallocated when the session (GDALAsyncReader) is destroyed with EndAsyncReader(). It should be deallocated by the application at that point.

Additional information on asynchronous IO in GDAL may be found at: https://gdal.org/development/rfc/rfc24_progressive_data_support.html

This method is the same as the C++ GDALDataset::BeginAsyncReader() method.

参数

• hDS -- handle to the dataset object.

• nXOff -- The pixel offset to the top left corner of the region of the band to be accessed. This would be zero to start from the left side.

• nYOff -- The line offset to the top left corner of the region of the band to be accessed. This would be zero to start from the top.

• nXSize -- The width of the region of the band to be accessed in pixels.

• nYSize -- The height of the region of the band to be accessed in lines.

• pBuf -- The buffer into which the data should be read. This buffer must contain at least nBufXSize * nBufYSize * nBandCount words of type eBufType. It is organized in left to right,top to bottom pixel order. Spacing is controlled by the nPixelSpace, and nLineSpace parameters.

• nBufXSize -- the width of the buffer image into which the desired region is to be read, or from which it is to be written.

• nBufYSize -- the height of the buffer image into which the desired region is to be read, or from which it is to be written.

• eBufType -- the type of the pixel values in the pData data buffer. The pixel values will automatically be translated to/from the GDALRasterBand data type as needed.

• nBandCount -- the number of bands being read or written.

• panBandMap -- the list of nBandCount band numbers being read/written. Note band numbers are 1 based. This may be NULL to select the first nBandCount bands.

• nPixelSpace -- The byte offset from the start of one pixel value in pData to the start of the next pixel value within a scanline. If defaulted (0) the size of the datatype eBufType is used.

• nLineSpace -- The byte offset from the start of one scanline in pData to the start of the next. If defaulted the size of the datatype eBufType * nBufXSize is used.

• nBandSpace -- the byte offset from the start of one bands data to the start of the next. If defaulted (zero) the value will be nLineSpace * nBufYSize implying band sequential organization of the data buffer.

• papszOptions -- Driver specific control options in a string list or NULL. Consult driver documentation for options supported.

返回

handle representing the request.

void GDALEndAsyncReader(GDALDatasetH hDS, GDALAsyncReaderH hAsynchReaderH)

End asynchronous request.

This method destroys an asynchronous io request and recovers all resources associated with it.

This method is the same as the C++ method GDALDataset::EndAsyncReader().

参数

• hDS -- handle to the dataset object.

• hAsyncReaderH -- handle returned by GDALBeginAsyncReader()

CPLErr GDALDatasetRasterIO(GDALDatasetH hDS, GDALRWFlag eRWFlag, int nDSXOff, int nDSYOff, int nDSXSize, int nDSYSize, void *pBuffer, int nBXSize, int nBYSize, GDALDataType eBDataType, int nBandCount, int *panBandCount, int nPixelSpace, int nLineSpace, int nBandSpace)

Read/write a region of image data from multiple bands.

Use GDALDatasetRasterIOEx() if 64 bit spacings or extra arguments (resampling resolution, progress callback, etc. are needed)

参见

GDALDataset::RasterIO()

CPLErr GDALDatasetRasterIOEx(GDALDatasetH hDS, GDALRWFlag eRWFlag, int nDSXOff, int nDSYOff, int nDSXSize, int nDSYSize, void *pBuffer, int nBXSize, int nBYSize, GDALDataType eBDataType, int nBandCount, int *panBandCount, GSpacing nPixelSpace, GSpacing nLineSpace, GSpacing nBandSpace, GDALRasterIOExtraArg *psExtraArg)

Read/write a region of image data from multiple bands.

参见

GDALDataset::RasterIO()

Since

GDAL 2.0

CPLErr GDALDatasetAdviseRead(GDALDatasetH hDS, int nDSXOff, int nDSYOff, int nDSXSize, int nDSYSize, int nBXSize, int nBYSize, GDALDataType eBDataType, int nBandCount, int *panBandCount, CSLConstList papszOptions)

Advise driver of upcoming read requests.

参见

GDALDataset::AdviseRead()

const char *GDALGetProjectionRef(GDALDatasetH)

Fetch the projection definition string for this dataset.

参见

GDALDataset::GetProjectionRef()

OGRSpatialReferenceH GDALGetSpatialRef(GDALDatasetH)

Fetch the spatial reference for this dataset.

参见

GDALDataset::GetSpatialRef()

Since

GDAL 3.0

CPLErr GDALSetProjection(GDALDatasetH, const char*)

Set the projection reference string for this dataset.

参见

GDALDataset::SetProjection()

CPLErr GDALSetSpatialRef(GDALDatasetH, OGRSpatialReferenceH)

Set the spatial reference system for this dataset.

参见

GDALDataset::SetSpatialRef()

Since

GDAL 3.0

CPLErr GDALGetGeoTransform(GDALDatasetH, double*)

Fetch the affine transformation coefficients.

参见

GDALDataset::GetGeoTransform()

CPLErr GDALSetGeoTransform(GDALDatasetH, double*)

Set the affine transformation coefficients.

参见

GDALDataset::SetGeoTransform()

int GDALGetGCPCount(GDALDatasetH)

Get number of GCPs.

参见

GDALDataset::GetGCPCount()

const char *GDALGetGCPProjection(GDALDatasetH)

Get output projection for GCPs.

参见

GDALDataset::GetGCPProjection()

OGRSpatialReferenceH GDALGetGCPSpatialRef(GDALDatasetH)

Get output spatial reference system for GCPs.

参见

GDALDataset::GetGCPSpatialRef()

Since

GDAL 3.0

const GDAL_GCP *GDALGetGCPs(GDALDatasetH)

Fetch GCPs.

参见

GDALDataset::GetGCPs()

CPLErr GDALSetGCPs(GDALDatasetH, int, const GDAL_GCP*, const char*)

Assign GCPs.

参见

GDALDataset::SetGCPs(int, const GDAL_GCP*, const char*)

CPLErr GDALSetGCPs2(GDALDatasetH, int, const GDAL_GCP*, OGRSpatialReferenceH)

Assign GCPs.

参见

GDALDataset::SetGCPs(int, const GDAL_GCP*, const OGRSpatialReference*)

Since

GDAL 3.0

void *GDALGetInternalHandle(GDALDatasetH, const char*)

Fetch a format specific internally meaningful handle.

参见

GDALDataset::GetInternalHandle()

int GDALReferenceDataset(GDALDatasetH)

Add one to dataset reference count.

参见

GDALDataset::Reference()

int GDALDereferenceDataset(GDALDatasetH)

Subtract one from dataset reference count.

参见

GDALDataset::Dereference()

int GDALReleaseDataset(GDALDatasetH)

Drop a reference to this object, and destroy if no longer referenced.

参见

GDALDataset::ReleaseRef()

Since

GDAL 2.2

CPLErr GDALBuildOverviews(GDALDatasetH, const char*, int, int*, int, int*, GDALProgressFunc, void*)

Build raster overview(s)

参见

GDALDataset::BuildOverviews()

void GDALGetOpenDatasets(GDALDatasetH **hDS, int *pnCount)

Fetch all open GDAL dataset handles.

参见

GDALDataset::GetOpenDatasets()

int GDALGetAccess(GDALDatasetH hDS)

Return access flag.

参见

GDALDataset::GetAccess()

void GDALFlushCache(GDALDatasetH hDS)

Flush all write cached data to disk.

参见

GDALDataset::FlushCache().

CPLErr GDALCreateDatasetMaskBand(GDALDatasetH hDS, int nFlags)

Adds a mask band to the dataset.

参见

GDALDataset::CreateMaskBand()

CPLErr GDALDatasetCopyWholeRaster(GDALDatasetH hSrcDS, GDALDatasetH hDstDS, CSLConstList papszOptions, GDALProgressFunc pfnProgress, void *pProgressData)

Copy all dataset raster data.

This function copies the complete raster contents of one dataset to another similarly configured dataset. The source and destination dataset must have the same number of bands, and the same width and height. The bands do not have to have the same data type.

This function is primarily intended to support implementation of driver specific CreateCopy() functions. It implements efficient copying, in particular "chunking" the copy in substantial blocks and, if appropriate, performing the transfer in a pixel interleaved fashion.

Currently the only papszOptions value supported are :

• "INTERLEAVE=PIXEL/BAND" to force pixel (resp. band) interleaved read and write access pattern (this does not modify the layout of the destination data)

• "COMPRESSED=YES" to force alignment on target dataset block sizes to achieve best compression.

• "SKIP_HOLES=YES" to skip chunks for which GDALGetDataCoverageStatus() returns GDAL_DATA_COVERAGE_STATUS_EMPTY (GDAL >= 2.2)

More options may be supported in the future.

参数

• hSrcDS -- the source dataset

• hDstDS -- the destination dataset

• papszOptions -- transfer hints in "StringList" Name=Value format.

• pfnProgress -- progress reporting function.

• pProgressData -- callback data for progress function.

返回

CE_None on success, or CE_Failure on failure.

CPLErr GDALRasterBandCopyWholeRaster(GDALRasterBandH hSrcBand, GDALRasterBandH hDstBand, const char *const *constpapszOptions, GDALProgressFunc pfnProgress, void *pProgressData)

Copy a whole raster band.

This function copies the complete raster contents of one band to another similarly configured band. The source and destination bands must have the same width and height. The bands do not have to have the same data type.

It implements efficient copying, in particular "chunking" the copy in substantial blocks.

Currently the only papszOptions value supported are :

• "COMPRESSED=YES" to force alignment on target dataset block sizes to achieve best compression.

• "SKIP_HOLES=YES" to skip chunks for which GDALGetDataCoverageStatus() returns GDAL_DATA_COVERAGE_STATUS_EMPTY (GDAL >= 2.2)

参数

• hSrcBand -- the source band

• hDstBand -- the destination band

• papszOptions -- transfer hints in "StringList" Name=Value format.

• pfnProgress -- progress reporting function.

• pProgressData -- callback data for progress function.

返回

CE_None on success, or CE_Failure on failure.

CPLErr GDALRegenerateOverviews(GDALRasterBandH hSrcBand, int nOverviewCount, GDALRasterBandH *pahOverviewBands, const char *pszResampling, GDALProgressFunc pfnProgress, void *pProgressData)

Generate downsampled overviews.

This function will generate one or more overview images from a base image using the requested downsampling algorithm. Its primary use is for generating overviews via GDALDataset::BuildOverviews(), but it can also be used to generate downsampled images in one file from another outside the overview architecture.

The output bands need to exist in advance.

The full set of resampling algorithms is documented in GDALDataset::BuildOverviews().

This function will honour properly NODATA_VALUES tuples (special dataset metadata) so that only a given RGB triplet (in case of a RGB image) will be considered as the nodata value and not each value of the triplet independently per band.

Starting with GDAL 3.2, the GDAL_NUM_THREADS configuration option can be set to "ALL_CPUS" or a integer value to specify the number of threads to use for overview computation.

参数

• hSrcBand -- the source (base level) band.

• nOverviewCount -- the number of downsampled bands being generated.

• pahOvrBands -- the list of downsampled bands to be generated.

• pszResampling -- Resampling algorithm (e.g. "AVERAGE").

• pfnProgress -- progress report function.

• pProgressData -- progress function callback data.

返回

CE_None on success or CE_Failure on failure.

int GDALDatasetGetLayerCount(GDALDatasetH)

Get the number of layers in this dataset.

This function is the same as the C++ method GDALDataset::GetLayerCount()

Since

GDAL 2.0

参数

hDS -- the dataset handle.

返回

layer count.

OGRLayerH GDALDatasetGetLayer(GDALDatasetH, int)

Fetch a layer by index.

The returned layer remains owned by the GDALDataset and should not be deleted by the application.

This function is the same as the C++ method GDALDataset::GetLayer()

Since

GDAL 2.0

参数

• hDS -- the dataset handle.

• iLayer -- a layer number between 0 and GetLayerCount()-1.

返回

the layer, or NULL if iLayer is out of range or an error occurs.

OGRLayerH GDALDatasetGetLayerByName(GDALDatasetH, const char*)

Fetch a layer by name.

The returned layer remains owned by the GDALDataset and should not be deleted by the application.

This function is the same as the C++ method GDALDataset::GetLayerByName()

Since

GDAL 2.0

参数

• hDS -- the dataset handle.

• pszName -- the layer name of the layer to fetch.

返回

the layer, or NULL if Layer is not found or an error occurs.

int GDALDatasetIsLayerPrivate(GDALDatasetH, int)

Returns true if the layer at the specified index is deemed a private or system table, or an internal detail only.

This function is the same as the C++ method GDALDataset::IsLayerPrivate()

Since

GDAL 3.4

参数

• hDS -- the dataset handle.

• iLayer -- a layer number between 0 and GetLayerCount()-1.

返回

true if the layer is a private or system table.

OGRErr GDALDatasetDeleteLayer(GDALDatasetH, int)

Delete the indicated layer from the datasource.

If this function is supported the ODsCDeleteLayer capability will test TRUE on the GDALDataset.

This method is the same as the C++ method GDALDataset::DeleteLayer().

Since

GDAL 2.0

参数

• hDS -- the dataset handle.

• iLayer -- the index of the layer to delete.

返回

OGRERR_NONE on success, or OGRERR_UNSUPPORTED_OPERATION if deleting layers is not supported for this datasource.

OGRLayerH GDALDatasetCreateLayer(GDALDatasetH, const char*, OGRSpatialReferenceH, OGRwkbGeometryType, CSLConstList)

This function attempts to create a new layer on the dataset with the indicated name, coordinate system, geometry type.

The papszOptions argument can be used to control driver specific creation options. These options are normally documented in the format specific documentation.

This method is the same as the C++ method GDALDataset::CreateLayer().

Example:

#include "gdal.h"
#include "cpl_string.h"

...

        OGRLayerH  hLayer;
        char     **papszOptions;

        if( !GDALDatasetTestCapability( hDS, ODsCCreateLayer ) )
        {
        ...
        }

        papszOptions = CSLSetNameValue( papszOptions, "DIM", "2" );
        hLayer = GDALDatasetCreateLayer( hDS, "NewLayer", NULL, wkbUnknown,
                                         papszOptions );
        CSLDestroy( papszOptions );

        if( hLayer == NULL )
        {
            ...
        }

Since

GDAL 2.0

参数

• hDS -- the dataset handle

• pszName -- the name for the new layer. This should ideally not match any existing layer on the datasource.

• hSpatialRef -- the coordinate system to use for the new layer, or NULL if no coordinate system is available. The driver might only increase the reference counter of the object to take ownership, and not make a full copy, so do not use OSRDestroySpatialReference(), but OSRRelease() instead when you are done with the object.

• eGType -- the geometry type for the layer. Use wkbUnknown if there are no constraints on the types geometry to be written.

• papszOptions -- a StringList of name=value options. Options are driver specific.

返回

NULL is returned on failure, or a new OGRLayer handle on success.

OGRLayerH GDALDatasetCopyLayer(GDALDatasetH, OGRLayerH, const char*, CSLConstList)

Duplicate an existing layer.

This function creates a new layer, duplicate the field definitions of the source layer and then duplicate each features of the source layer. The papszOptions argument can be used to control driver specific creation options. These options are normally documented in the format specific documentation. The source layer may come from another dataset.

This method is the same as the C++ method GDALDataset::CopyLayer()

Since

GDAL 2.0

参数

• hDS -- the dataset handle.

• hSrcLayer -- source layer.

• pszNewName -- the name of the layer to create.

• papszOptions -- a StringList of name=value options. Options are driver specific.

返回

a handle to the layer, or NULL if an error occurs.

void GDALDatasetResetReading(GDALDatasetH)

Reset feature reading to start on the first feature.

This affects GDALDatasetGetNextFeature().

Depending on drivers, this may also have the side effect of calling OGR_L_ResetReading() on the layers of this dataset.

This method is the same as the C++ method GDALDataset::ResetReading()

Since

GDAL 2.2

参数

hDS -- dataset handle

OGRFeatureH GDALDatasetGetNextFeature(GDALDatasetH hDS, OGRLayerH *phBelongingLayer, double *pdfProgressPct, GDALProgressFunc pfnProgress, void *pProgressData)

Fetch the next available feature from this dataset.

This method is intended for the few drivers where OGR_L_GetNextFeature() is not efficient, but in general OGR_L_GetNextFeature() is a more natural API.

The returned feature becomes the responsibility of the caller to delete with OGRFeature::DestroyFeature().

Depending on the driver, this method may return features from layers in a non sequential way. This is what may happen when the ODsCRandomLayerRead capability is declared (for example for the OSM and GMLAS drivers). When datasets declare this capability, it is strongly advised to use GDALDataset::GetNextFeature() instead of OGRLayer::GetNextFeature(), as the later might have a slow, incomplete or stub implementation.

The default implementation, used by most drivers, will however iterate over each layer, and then over each feature within this layer.

This method takes into account spatial and attribute filters set on layers that will be iterated upon.

The ResetReading() method can be used to start at the beginning again.

Depending on drivers, this may also have the side effect of calling OGRLayer::GetNextFeature() on the layers of this dataset.

This method is the same as the C++ method GDALDataset::GetNextFeature()

Since

GDAL 2.2

参数

• hDS -- dataset handle.

• phBelongingLayer -- a pointer to a OGRLayer* variable to receive the layer to which the object belongs to, or NULL. It is possible that the output of *ppoBelongingLayer to be NULL despite the feature not being NULL.

• pdfProgressPct -- a pointer to a double variable to receive the percentage progress (in [0,1] range), or NULL. On return, the pointed value might be negative if determining the progress is not possible.

• pfnProgress -- a progress callback to report progress (for GetNextFeature() calls that might have a long duration) and offer cancellation possibility, or NULL

• pProgressData -- user data provided to pfnProgress, or NULL

返回

a feature, or NULL if no more features are available.

int GDALDatasetTestCapability(GDALDatasetH, const char*)

Test if capability is available.

One of the following dataset capability names can be passed into this function, and a TRUE or FALSE value will be returned indicating whether or not the capability is available for this object.

• ODsCCreateLayer: True if this datasource can create new layers.

• ODsCDeleteLayer: True if this datasource can delete existing layers.

• ODsCCreateGeomFieldAfterCreateLayer: True if the layers of this datasource support CreateGeomField() just after layer creation.

• ODsCCurveGeometries: True if this datasource supports curve geometries.

• ODsCTransactions: True if this datasource supports (efficient) transactions.

• ODsCEmulatedTransactions: True if this datasource supports transactions through emulation.

• ODsCRandomLayerRead: True if this datasource has a dedicated GetNextFeature() implementation, potentially returning features from layers in a non sequential way.

• ODsCRandomLayerWrite: True if this datasource supports calling CreateFeature() on layers in a non sequential way.

The #define macro forms of the capability names should be used in preference to the strings themselves to avoid misspelling.

This function is the same as the C++ method GDALDataset::TestCapability()

Since

GDAL 2.0

参数

• hDS -- the dataset handle.

• pszCap -- the capability to test.

返回

TRUE if capability available otherwise FALSE.

OGRLayerH GDALDatasetExecuteSQL(GDALDatasetH, const char*, OGRGeometryH, const char*)

Execute an SQL statement against the data store.

The result of an SQL query is either NULL for statements that are in error, or that have no results set, or an OGRLayer pointer representing a results set from the query. Note that this OGRLayer is in addition to the layers in the data store and must be destroyed with ReleaseResultSet() before the dataset is closed (destroyed).

This method is the same as the C++ method GDALDataset::ExecuteSQL()

For more information on the SQL dialect supported internally by OGR review the OGR SQL document. Some drivers (i.e. Oracle and PostGIS) pass the SQL directly through to the underlying RDBMS.

Starting with OGR 1.10, the SQLITE dialect can also be used.

Since

GDAL 2.0

参数

• hDS -- the dataset handle.

• pszStatement -- the SQL statement to execute.

• hSpatialFilter -- geometry which represents a spatial filter. Can be NULL.

• pszDialect -- allows control of the statement dialect. If set to NULL, the OGR SQL engine will be used, except for RDBMS drivers that will use their dedicated SQL engine, unless OGRSQL is explicitly passed as the dialect. Starting with OGR 1.10, the SQLITE dialect can also be used.

返回

an OGRLayer containing the results of the query. Deallocate with GDALDatasetReleaseResultSet().

OGRErr GDALDatasetAbortSQL(GDALDatasetH)

Abort any SQL statement running in the data store.

This function can be safely called from any thread (pending that the dataset object is still alive). Driver implementations will make sure that it can be called in a thread-safe way.

This might not be implemented by all drivers. At time of writing, only SQLite, GPKG and PG drivers implement it

This method is the same as the C++ method GDALDataset::AbortSQL()

Since

GDAL 3.2.0

参数

hDS -- the dataset handle.

返回

OGRERR_NONE on success, or OGRERR_UNSUPPORTED_OPERATION if AbortSQL is not supported for this datasource. .

void GDALDatasetReleaseResultSet(GDALDatasetH, OGRLayerH)

Release results of ExecuteSQL().

This function should only be used to deallocate OGRLayers resulting from an ExecuteSQL() call on the same GDALDataset. Failure to deallocate a results set before destroying the GDALDataset may cause errors.

This function is the same as the C++ method GDALDataset::ReleaseResultSet()

Since

GDAL 2.0

参数

• hDS -- the dataset handle.

• hLayer -- the result of a previous ExecuteSQL() call.

OGRStyleTableH GDALDatasetGetStyleTable(GDALDatasetH)

Returns dataset style table.

This function is the same as the C++ method GDALDataset::GetStyleTable()

Since

GDAL 2.0

参数

hDS -- the dataset handle

返回

handle to a style table which should not be modified or freed by the caller.

void GDALDatasetSetStyleTableDirectly(GDALDatasetH, OGRStyleTableH)

Set dataset style table.

This function operate exactly as GDALDatasetSetStyleTable() except that it assumes ownership of the passed table.

This function is the same as the C++ method GDALDataset::SetStyleTableDirectly()

Since

GDAL 2.0

参数

• hDS -- the dataset handle

• hStyleTable -- style table handle to set

void GDALDatasetSetStyleTable(GDALDatasetH, OGRStyleTableH)

Set dataset style table.

This function operate exactly as GDALDatasetSetStyleTableDirectly() except that it assumes ownership of the passed table.

This function is the same as the C++ method GDALDataset::SetStyleTable()

Since

GDAL 2.0

参数

• hDS -- the dataset handle

• hStyleTable -- style table handle to set

OGRErr GDALDatasetStartTransaction(GDALDatasetH hDS, int bForce)

For datasources which support transactions, StartTransaction creates a transaction.

If starting the transaction fails, will return OGRERR_FAILURE. Datasources which do not support transactions will always return OGRERR_UNSUPPORTED_OPERATION.

Nested transactions are not supported.

All changes done after the start of the transaction are definitely applied in the datasource if CommitTransaction() is called. They may be canceled by calling RollbackTransaction() instead.

At the time of writing, transactions only apply on vector layers.

Datasets that support transactions will advertise the ODsCTransactions capability. Use of transactions at dataset level is generally preferred to transactions at layer level, whose scope is rarely limited to the layer from which it was started.

In case StartTransaction() fails, neither CommitTransaction() or RollbackTransaction() should be called.

If an error occurs after a successful StartTransaction(), the whole transaction may or may not be implicitly canceled, depending on drivers. (e.g. the PG driver will cancel it, SQLite/GPKG not). In any case, in the event of an error, an explicit call to RollbackTransaction() should be done to keep things balanced.

By default, when bForce is set to FALSE, only "efficient" transactions will be attempted. Some drivers may offer an emulation of transactions, but sometimes with significant overhead, in which case the user must explicitly allow for such an emulation by setting bForce to TRUE. Drivers that offer emulated transactions should advertise the ODsCEmulatedTransactions capability (and not ODsCTransactions).

This function is the same as the C++ method GDALDataset::StartTransaction()

Since

GDAL 2.0

参数

• hDS -- the dataset handle.

• bForce -- can be set to TRUE if an emulation, possibly slow, of a transaction mechanism is acceptable.

返回

OGRERR_NONE on success.

OGRErr GDALDatasetCommitTransaction(GDALDatasetH hDS)

For datasources which support transactions, CommitTransaction commits a transaction.

If no transaction is active, or the commit fails, will return OGRERR_FAILURE. Datasources which do not support transactions will always return OGRERR_UNSUPPORTED_OPERATION.

Depending on drivers, this may or may not abort layer sequential readings that are active.

This function is the same as the C++ method GDALDataset::CommitTransaction()

Since

GDAL 2.0

返回

OGRERR_NONE on success.

OGRErr GDALDatasetRollbackTransaction(GDALDatasetH hDS)

For datasources which support transactions, RollbackTransaction will roll back a datasource to its state before the start of the current transaction.

If no transaction is active, or the rollback fails, will return OGRERR_FAILURE. Datasources which do not support transactions will always return OGRERR_UNSUPPORTED_OPERATION.

This function is the same as the C++ method GDALDataset::RollbackTransaction().

Since

GDAL 2.0

返回

OGRERR_NONE on success.

void GDALDatasetClearStatistics(GDALDatasetH hDS)

Clear statistics.

This is the same as the C++ method GDALDataset::ClearStatistics().

Since

GDAL 3.2

char **GDALDatasetGetFieldDomainNames(GDALDatasetH, CSLConstList)

Returns a list of the names of all field domains stored in the dataset.

This is the same as the C++ method GDALDataset::GetFieldDomainNames().

Since

GDAL 3.5

参数

• hDS -- Dataset handle.

• papszOptions -- Driver specific options determining how attributes should be retrieved. Pass nullptr for default behavior.

返回

list of field domain names, to be freed with CSLDestroy()

OGRFieldDomainH GDALDatasetGetFieldDomain(GDALDatasetH hDS, const char *pszName)

Get a field domain from its name.

This is the same as the C++ method GDALDataset::GetFieldDomain().

Since

GDAL 3.3

参数

• hDS -- Dataset handle.

• pszName -- Name of field domain.

返回

the field domain (ownership remains to the dataset), or nullptr if not found.

bool GDALDatasetAddFieldDomain(GDALDatasetH hDS, OGRFieldDomainH hFieldDomain, char **ppszFailureReason)

Add a field domain to the dataset.

Only a few drivers will support this operation, and some of them might only support it only for some types of field domains. At the time of writing (GDAL 3.3), only the Memory and GeoPackage drivers support this operation. A dataset having at least some support for this operation should report the ODsCAddFieldDomain dataset capability.

Anticipated failures will not be emitted through the CPLError() infrastructure, but will be reported in the ppszFailureReason output parameter.

Since

GDAL 3.3

参数

• hDS -- Dataset handle.

• hFieldDomain -- The domain definition. Contrary to the C++ version, the passed object is copied.

• ppszFailureReason -- Output parameter. Will contain an error message if an error occurs (*ppszFailureReason to be freed with CPLFree). May be NULL.

返回

true in case of success.

bool GDALDatasetDeleteFieldDomain(GDALDatasetH hDS, const char *pszName, char **ppszFailureReason)

Removes a field domain from the dataset.

Only a few drivers will support this operation.

At the time of writing (GDAL 3.5), only the Memory and GeoPackage drivers support this operation. A dataset having at least some support for this operation should report the ODsCDeleteFieldDomain dataset capability.

Anticipated failures will not be emitted through the CPLError() infrastructure, but will be reported in the ppszFailureReason output parameter.

Since

GDAL 3.3

参数

• hDS -- Dataset handle.

• pszName -- The domain name.

• ppszFailureReason -- Output parameter. Will contain an error message if an error occurs (*ppszFailureReason to be freed with CPLFree). May be NULL.

返回

true in case of success.

bool GDALDatasetUpdateFieldDomain(GDALDatasetH hDS, OGRFieldDomainH hFieldDomain, char **ppszFailureReason)

Updates an existing field domain by replacing its definition.

The existing field domain with matching name will be replaced.

Only a few drivers will support this operation, and some of them might only support it only for some types of field domains. At the time of writing (GDAL 3.5), only the Memory driver supports this operation. A dataset having at least some support for this operation should report the ODsCUpdateFieldDomain dataset capability.

Anticipated failures will not be emitted through the CPLError() infrastructure, but will be reported in the failureReason output parameter.

Since

GDAL 3.5

参数

• hDS -- Dataset handle.

• hFieldDomain -- The domain definition. Contrary to the C++ version, the passed object is copied.

• ppszFailureReason -- Output parameter. Will contain an error message if an error occurs (*ppszFailureReason to be freed with CPLFree). May be NULL.

返回

true in case of success.

GDALDataType GDALGetRasterDataType(GDALRasterBandH)

Fetch the pixel data type for this band.

参见

GDALRasterBand::GetRasterDataType()

void GDALGetBlockSize(GDALRasterBandH, int *pnXSize, int *pnYSize)

Fetch the "natural" block size of this band.

参见

GDALRasterBand::GetBlockSize()

CPLErr GDALGetActualBlockSize(GDALRasterBandH, int nXBlockOff, int nYBlockOff, int *pnXValid, int *pnYValid)

Retrieve the actual block size for a given block offset.

参见

GDALRasterBand::GetActualBlockSize()

CPLErr GDALRasterAdviseRead(GDALRasterBandH hRB, int nDSXOff, int nDSYOff, int nDSXSize, int nDSYSize, int nBXSize, int nBYSize, GDALDataType eBDataType, CSLConstList papszOptions)

Advise driver of upcoming read requests.

参见

GDALRasterBand::AdviseRead()

CPLErr GDALRasterIO(GDALRasterBandH hRBand, GDALRWFlag eRWFlag, int nDSXOff, int nDSYOff, int nDSXSize, int nDSYSize, void *pBuffer, int nBXSize, int nBYSize, GDALDataType eBDataType, int nPixelSpace, int nLineSpace)

Read/write a region of image data for this band.

Use GDALRasterIOEx() if 64 bit spacings or extra arguments (resampling resolution, progress callback, etc. are needed)

参见

GDALRasterBand::RasterIO()

CPLErr GDALRasterIOEx(GDALRasterBandH hRBand, GDALRWFlag eRWFlag, int nDSXOff, int nDSYOff, int nDSXSize, int nDSYSize, void *pBuffer, int nBXSize, int nBYSize, GDALDataType eBDataType, GSpacing nPixelSpace, GSpacing nLineSpace, GDALRasterIOExtraArg *psExtraArg)

Read/write a region of image data for this band.

参见

GDALRasterBand::RasterIO()

Since

GDAL 2.0

CPLErr GDALReadBlock(GDALRasterBandH, int, int, void*)

Read a block of image data efficiently.

参见

GDALRasterBand::ReadBlock()

CPLErr GDALWriteBlock(GDALRasterBandH, int, int, void*)

Write a block of image data efficiently.

参见

GDALRasterBand::WriteBlock()

int GDALGetRasterBandXSize(GDALRasterBandH)

Fetch XSize of raster.

参见

GDALRasterBand::GetXSize()

int GDALGetRasterBandYSize(GDALRasterBandH)

Fetch YSize of raster.

参见

GDALRasterBand::GetYSize()

GDALAccess GDALGetRasterAccess(GDALRasterBandH)

Find out if we have update permission for this band.

参见

GDALRasterBand::GetAccess()

int GDALGetBandNumber(GDALRasterBandH)

Fetch the band number.

参见

GDALRasterBand::GetBand()

GDALDatasetH GDALGetBandDataset(GDALRasterBandH)

Fetch the owning dataset handle.

参见

GDALRasterBand::GetDataset()

GDALColorInterp GDALGetRasterColorInterpretation(GDALRasterBandH)

How should this band be interpreted as color?

参见

GDALRasterBand::GetColorInterpretation()

CPLErr GDALSetRasterColorInterpretation(GDALRasterBandH, GDALColorInterp)

Set color interpretation of a band.

参见

GDALRasterBand::SetColorInterpretation()

GDALColorTableH GDALGetRasterColorTable(GDALRasterBandH)

Fetch the color table associated with band.

参见

GDALRasterBand::GetColorTable()

CPLErr GDALSetRasterColorTable(GDALRasterBandH, GDALColorTableH)

Set the raster color table.

参见

GDALRasterBand::SetColorTable()

int GDALHasArbitraryOverviews(GDALRasterBandH)

Check for arbitrary overviews.

参见

GDALRasterBand::HasArbitraryOverviews()

int GDALGetOverviewCount(GDALRasterBandH)

Return the number of overview layers available.

参见

GDALRasterBand::GetOverviewCount()

GDALRasterBandH GDALGetOverview(GDALRasterBandH, int)

Fetch overview raster band object.

参见

GDALRasterBand::GetOverview()

double GDALGetRasterNoDataValue(GDALRasterBandH, int*)

Fetch the no data value for this band.

参见

GDALRasterBand::GetNoDataValue()

int64_t GDALGetRasterNoDataValueAsInt64(GDALRasterBandH, int*)

Fetch the no data value for this band.

This function should ONLY be called on rasters whose data type is GDT_Int64.

参见

GDALRasterBand::GetNoDataValueAsInt64()

Since

GDAL 3.5

uint64_t GDALGetRasterNoDataValueAsUInt64(GDALRasterBandH, int*)

Fetch the no data value for this band.

This function should ONLY be called on rasters whose data type is GDT_UInt64.

参见

GDALRasterBand::GetNoDataValueAsUInt64()

Since

GDAL 3.5

CPLErr GDALSetRasterNoDataValue(GDALRasterBandH, double)

Set the no data value for this band.

Depending on drivers, changing the no data value may or may not have an effect on the pixel values of a raster that has just been created. It is thus advised to explicitly called Fill() if the intent is to initialize the raster to the nodata value. In any case, changing an existing no data value, when one already exists and the dataset exists or has been initialized, has no effect on the pixel whose value matched the previous nodata value.

For rasters of type GDT_Int64 or GDT_UInt64, whose nodata value cannot always be represented by a double, use GDALSetRasterNoDataValueAsInt64() or GDALSetRasterNoDataValueAsUInt64() instead.

参见

GDALRasterBand::SetNoDataValue()

CPLErr GDALSetRasterNoDataValueAsInt64(GDALRasterBandH, int64_t)

Set the no data value for this band.

This function should ONLY be called on rasters whose data type is GDT_Int64.

Depending on drivers, changing the no data value may or may not have an effect on the pixel values of a raster that has just been created. It is thus advised to explicitly called Fill() if the intent is to initialize the raster to the nodata value. In ay case, changing an existing no data value, when one already exists and the dataset exists or has been initialized, has no effect on the pixel whose value matched the previous nodata value.

参见

GDALRasterBand::SetNoDataValueAsInt64()

Since

GDAL 3.5

CPLErr GDALSetRasterNoDataValueAsUInt64(GDALRasterBandH, uint64_t)

Set the no data value for this band.

This function should ONLY be called on rasters whose data type is GDT_UInt64.

Depending on drivers, changing the no data value may or may not have an effect on the pixel values of a raster that has just been created. It is thus advised to explicitly called Fill() if the intent is to initialize the raster to the nodata value. In ay case, changing an existing no data value, when one already exists and the dataset exists or has been initialized, has no effect on the pixel whose value matched the previous nodata value.

参见

GDALRasterBand::SetNoDataValueAsUInt64()

Since

GDAL 3.5

CPLErr GDALDeleteRasterNoDataValue(GDALRasterBandH)

Remove the no data value for this band.

参见

GDALRasterBand::DeleteNoDataValue()

Since

GDAL 2.1

char **GDALGetRasterCategoryNames(GDALRasterBandH)

Fetch the list of category names for this raster.

参见

GDALRasterBand::GetCategoryNames()

CPLErr GDALSetRasterCategoryNames(GDALRasterBandH, CSLConstList)

Set the category names for this band.

参见

GDALRasterBand::SetCategoryNames()

double GDALGetRasterMinimum(GDALRasterBandH, int *pbSuccess)

Fetch the minimum value for this band.

参见

GDALRasterBand::GetMinimum()

double GDALGetRasterMaximum(GDALRasterBandH, int *pbSuccess)

Fetch the maximum value for this band.

参见

GDALRasterBand::GetMaximum()

CPLErr GDALGetRasterStatistics(GDALRasterBandH, int bApproxOK, int bForce, double *pdfMin, double *pdfMax, double *pdfMean, double *pdfStdDev)

Fetch image statistics.

参见

GDALRasterBand::GetStatistics()

CPLErr GDALComputeRasterStatistics(GDALRasterBandH, int bApproxOK, double *pdfMin, double *pdfMax, double *pdfMean, double *pdfStdDev, GDALProgressFunc pfnProgress, void *pProgressData)

Compute image statistics.

参见

GDALRasterBand::ComputeStatistics()

CPLErr GDALSetRasterStatistics(GDALRasterBandH hBand, double dfMin, double dfMax, double dfMean, double dfStdDev)

Set statistics on band.

参见

GDALRasterBand::SetStatistics()

GDALMDArrayH GDALRasterBandAsMDArray(GDALRasterBandH)

Return a view of this raster band as a 2D multidimensional GDALMDArray.

The band must be linked to a GDALDataset. If this dataset is not already marked as shared, it will be, so that the returned array holds a reference to it.

If the dataset has a geotransform attached, the X and Y dimensions of the returned array will have an associated indexing variable.

The returned pointer must be released with GDALMDArrayRelease().

This is the same as the C++ method GDALRasterBand::AsMDArray().

Since

GDAL 3.1

返回

a new array, or NULL.

const char *GDALGetRasterUnitType(GDALRasterBandH)

Return raster unit type.

参见

GDALRasterBand::GetUnitType()

CPLErr GDALSetRasterUnitType(GDALRasterBandH hBand, const char *pszNewValue)

Set unit type.

参见

GDALRasterBand::SetUnitType()

Since

GDAL 1.8.0

double GDALGetRasterOffset(GDALRasterBandH, int *pbSuccess)

Fetch the raster value offset.

参见

GDALRasterBand::GetOffset()

CPLErr GDALSetRasterOffset(GDALRasterBandH hBand, double dfNewOffset)

Set scaling offset.

参见

GDALRasterBand::SetOffset()

double GDALGetRasterScale(GDALRasterBandH, int *pbSuccess)

Fetch the raster value scale.

参见

GDALRasterBand::GetScale()

CPLErr GDALSetRasterScale(GDALRasterBandH hBand, double dfNewOffset)

Set scaling ratio.

参见

GDALRasterBand::SetScale()

void GDALComputeRasterMinMax(GDALRasterBandH hBand, int bApproxOK, double adfMinMax[2])

Compute the min/max values for a band.

参见

GDALRasterBand::ComputeRasterMinMax()

CPLErr GDALFlushRasterCache(GDALRasterBandH hBand)

Flush raster data cache.

参见

GDALRasterBand::FlushCache()

CPLErr GDALGetRasterHistogram(GDALRasterBandH hBand, double dfMin, double dfMax, int nBuckets, int *panHistogram, int bIncludeOutOfRange, int bApproxOK, GDALProgressFunc pfnProgress, void *pProgressData)

Compute raster histogram.

Use GDALGetRasterHistogramEx() instead to get correct counts for values exceeding 2 billion.

参见

GDALRasterBand::GetHistogram()

参见

GDALGetRasterHistogramEx()

CPLErr GDALGetRasterHistogramEx(GDALRasterBandH hBand, double dfMin, double dfMax, int nBuckets, GUIntBig *panHistogram, int bIncludeOutOfRange, int bApproxOK, GDALProgressFunc pfnProgress, void *pProgressData)

Compute raster histogram.

参见

GDALRasterBand::GetHistogram()

Since

GDAL 2.0

CPLErr GDALGetDefaultHistogram(GDALRasterBandH hBand, double *pdfMin, double *pdfMax, int *pnBuckets, int **ppanHistogram, int bForce, GDALProgressFunc pfnProgress, void *pProgressData)

Fetch default raster histogram.

Use GDALGetRasterHistogramEx() instead to get correct counts for values exceeding 2 billion.

参见

GDALRasterBand::GDALGetDefaultHistogram()

参见

GDALGetRasterHistogramEx()

CPLErr GDALGetDefaultHistogramEx(GDALRasterBandH hBand, double *pdfMin, double *pdfMax, int *pnBuckets, GUIntBig **ppanHistogram, int bForce, GDALProgressFunc pfnProgress, void *pProgressData)

Fetch default raster histogram.

参见

GDALRasterBand::GetDefaultHistogram()

Since

GDAL 2.0

CPLErr GDALSetDefaultHistogram(GDALRasterBandH hBand, double dfMin, double dfMax, int nBuckets, int *panHistogram)

Set default histogram.

Use GDALSetRasterHistogramEx() instead to be able to set counts exceeding 2 billion.

参见

GDALRasterBand::SetDefaultHistogram()

参见

GDALSetRasterHistogramEx()

CPLErr GDALSetDefaultHistogramEx(GDALRasterBandH hBand, double dfMin, double dfMax, int nBuckets, GUIntBig *panHistogram)

Set default histogram.

参见

GDALRasterBand::SetDefaultHistogram()

Since

GDAL 2.0

int GDALGetRandomRasterSample(GDALRasterBandH, int, float*)

Undocumented.

参数

• hBand -- undocumented.

• nSamples -- undocumented.

• pafSampleBuf -- undocumented.

返回

undocumented

GDALRasterBandH GDALGetRasterSampleOverview(GDALRasterBandH, int)

Fetch best sampling overview.

Use GDALGetRasterSampleOverviewEx() to be able to specify more than 2 billion samples.

参见

GDALRasterBand::GetRasterSampleOverview()

参见

GDALGetRasterSampleOverviewEx()

GDALRasterBandH GDALGetRasterSampleOverviewEx(GDALRasterBandH, GUIntBig)

Fetch best sampling overview.

参见

GDALRasterBand::GetRasterSampleOverview()

Since

GDAL 2.0

CPLErr GDALFillRaster(GDALRasterBandH hBand, double dfRealValue, double dfImaginaryValue)

Fill this band with a constant value.

参见

GDALRasterBand::Fill()

CPLErr GDALComputeBandStats(GDALRasterBandH hBand, int nSampleStep, double *pdfMean, double *pdfStdDev, GDALProgressFunc pfnProgress, void *pProgressData)

Undocumented.

参数

• hSrcBand -- undocumented.

• nSampleStep -- undocumented.

• pdfMean -- undocumented.

• pdfStdDev -- undocumented.

• pfnProgress -- undocumented.

• pProgressData -- undocumented.

返回

undocumented

CPLErr GDALOverviewMagnitudeCorrection(GDALRasterBandH hBaseBand, int nOverviewCount, GDALRasterBandH *pahOverviews, GDALProgressFunc pfnProgress, void *pProgressData)

Undocumented.

参数

• hBaseBand -- undocumented.

• nOverviewCount -- undocumented.

• pahOverviews -- undocumented.

• pfnProgress -- undocumented.

• pProgressData -- undocumented.

返回

undocumented

GDALRasterAttributeTableH GDALGetDefaultRAT(GDALRasterBandH hBand)

Fetch default Raster Attribute Table.

参见

GDALRasterBand::GetDefaultRAT()

CPLErr GDALSetDefaultRAT(GDALRasterBandH, GDALRasterAttributeTableH)

Set default Raster Attribute Table.

参见

GDALRasterBand::GDALSetDefaultRAT()

CPLErr GDALAddDerivedBandPixelFunc(const char *pszName, GDALDerivedPixelFunc pfnPixelFunc)

This adds a pixel function to the global list of available pixel functions for derived bands.

Pixel functions must be registered in this way before a derived band tries to access data.

Derived bands are stored with only the name of the pixel function that it will apply, and if a pixel function matching the name is not found the IRasterIO() call will do nothing.

参数

• pszName -- Name used to access pixel function

• pfnNewFunction -- Pixel function associated with name. An existing pixel function registered with the same name will be replaced with the new one.

返回

CE_None, invalid (NULL) parameters are currently ignored.

CPLErr GDALAddDerivedBandPixelFuncWithArgs(const char *pszName, GDALDerivedPixelFuncWithArgs pfnPixelFunc, const char *pszMetadata)

This adds a pixel function to the global list of available pixel functions for derived bands.

Pixel functions must be registered in this way before a derived band tries to access data.

Derived bands are stored with only the name of the pixel function that it will apply, and if a pixel function matching the name is not found the IRasterIO() call will do nothing.

Since

GDAL 3.4

参数

• pszName -- Name used to access pixel function

• pfnNewFunction -- Pixel function associated with name. An existing pixel function registered with the same name will be replaced with the new one.

• pszMetadata -- Pixel function metadata (not currently implemented)

返回

CE_None, invalid (NULL) parameters are currently ignored.

GDALRasterBandH GDALGetMaskBand(GDALRasterBandH hBand)

Return the mask band associated with the band.

参见

GDALRasterBand::GetMaskBand()

int GDALGetMaskFlags(GDALRasterBandH hBand)

Return the status flags of the mask band associated with the band.

参见

GDALRasterBand::GetMaskFlags()

CPLErr GDALCreateMaskBand(GDALRasterBandH hBand, int nFlags)

Adds a mask band to the current band.

参见

GDALRasterBand::CreateMaskBand()

bool GDALIsMaskBand(GDALRasterBandH hBand)

Returns whether a band is a mask band.

Mask band must be understood in the broad term: it can be a per-dataset mask band, an alpha band, or an implicit mask band. Typically the return of GetMaskBand()->IsMaskBand() should be true.

This function is the same as the C++ method GDALRasterBand::IsMaskBand()

参见

GDALRasterBand::IsMaskBand()

Since

GDAL 3.5.0

返回

true if the band is a mask band.

int GDALGetDataCoverageStatus(GDALRasterBandH hBand, int nXOff, int nYOff, int nXSize, int nYSize, int nMaskFlagStop, double *pdfDataPct)

Get the coverage status of a sub-window of the raster.

Returns whether a sub-window of the raster contains only data, only empty blocks or a mix of both. This function can be used to determine quickly if it is worth issuing RasterIO / ReadBlock requests in datasets that may be sparse.

Empty blocks are blocks that are generally not physically present in the file, and when read through GDAL, contain only pixels whose value is the nodata value when it is set, or whose value is 0 when the nodata value is not set.

The query is done in an efficient way without reading the actual pixel values. If not possible, or not implemented at all by the driver, GDAL_DATA_COVERAGE_STATUS_UNIMPLEMENTED | GDAL_DATA_COVERAGE_STATUS_DATA will be returned.

The values that can be returned by the function are the following, potentially combined with the binary or operator :

• GDAL_DATA_COVERAGE_STATUS_UNIMPLEMENTED : the driver does not implement GetDataCoverageStatus(). This flag should be returned together with GDAL_DATA_COVERAGE_STATUS_DATA.

• GDAL_DATA_COVERAGE_STATUS_DATA: There is (potentially) data in the queried window.

• GDAL_DATA_COVERAGE_STATUS_EMPTY: There is nodata in the queried window. This is typically identified by the concept of missing block in formats that supports it.

Note that GDAL_DATA_COVERAGE_STATUS_DATA might have false positives and should be interpreted more as hint of potential presence of data. For example if a GeoTIFF file is created with blocks filled with zeroes (or set to the nodata value), instead of using the missing block mechanism, GDAL_DATA_COVERAGE_STATUS_DATA will be returned. On the contrary, GDAL_DATA_COVERAGE_STATUS_EMPTY should have no false positives.

The nMaskFlagStop should be generally set to 0. It can be set to a binary-or'ed mask of the above mentioned values to enable a quick exiting of the function as soon as the computed mask matches the nMaskFlagStop. For example, you can issue a request on the whole raster with nMaskFlagStop = GDAL_DATA_COVERAGE_STATUS_EMPTY. As soon as one missing block is encountered, the function will exit, so that you can potentially refine the requested area to find which particular region(s) have missing blocks.

参见

GDALRasterBand::GetDataCoverageStatus()

备注

Added in GDAL 2.2

参数

• hBand -- raster band

• nXOff -- The pixel offset to the top left corner of the region of the band to be queried. This would be zero to start from the left side.

• nYOff -- The line offset to the top left corner of the region of the band to be queried. This would be zero to start from the top.

• nXSize -- The width of the region of the band to be queried in pixels.

• nYSize -- The height of the region of the band to be queried in lines.

• nMaskFlagStop -- 0, or a binary-or'ed mask of possible values GDAL_DATA_COVERAGE_STATUS_UNIMPLEMENTED, GDAL_DATA_COVERAGE_STATUS_DATA and GDAL_DATA_COVERAGE_STATUS_EMPTY. As soon as the computation of the coverage matches the mask, the computation will be stopped. *pdfDataPct will not be valid in that case.

• pdfDataPct -- Optional output parameter whose pointed value will be set to the (approximate) percentage in [0,100] of pixels in the queried sub-window that have valid values. The implementation might not always be able to compute it, in which case it will be set to a negative value.

返回

a binary-or'ed combination of possible values GDAL_DATA_COVERAGE_STATUS_UNIMPLEMENTED, GDAL_DATA_COVERAGE_STATUS_DATA and GDAL_DATA_COVERAGE_STATUS_EMPTY

GDALAsyncStatusType GDALARGetNextUpdatedRegion(GDALAsyncReaderH hARIO, double dfTimeout, int *pnXBufOff, int *pnYBufOff, int *pnXBufSize, int *pnYBufSize)

Get async IO update.

Provide an opportunity for an asynchronous IO request to update the image buffer and return an indication of the area of the buffer that has been updated.

The dfTimeout parameter can be used to wait for additional data to become available. The timeout does not limit the amount of time this method may spend actually processing available data.

The following return status are possible.

• GARIO_PENDING: No imagery was altered in the buffer, but there is still activity pending, and the application should continue to call GetNextUpdatedRegion() as time permits.

• GARIO_UPDATE: Some of the imagery has been updated, but there is still activity pending.

• GARIO_ERROR: Something has gone wrong. The asynchronous request should be ended.

• GARIO_COMPLETE: An update has occurred and there is no more pending work on this request. The request should be ended and the buffer used.

This is the same as GDALAsyncReader::GetNextUpdatedRegion()

参数

• hARIO -- handle to the async reader.

• dfTimeout -- the number of seconds to wait for additional updates. Use -1 to wait indefinitely, or zero to not wait at all if there is no data available.

• pnBufXOff -- location to return the X offset of the area of the request buffer that has been updated.

• pnBufYOff -- location to return the Y offset of the area of the request buffer that has been updated.

• pnBufXSize -- location to return the X size of the area of the request buffer that has been updated.

• pnBufYSize -- location to return the Y size of the area of the request buffer that has been updated.

返回

GARIO_ status, details described above.

int GDALARLockBuffer(GDALAsyncReaderH hARIO, double dfTimeout)

Lock image buffer.

Locks the image buffer passed into GDALDataset::BeginAsyncReader(). This is useful to ensure the image buffer is not being modified while it is being used by the application. UnlockBuffer() should be used to release this lock when it is no longer needed.

This is the same as GDALAsyncReader::LockBuffer()

参数

• hARIO -- handle to async reader.

• dfTimeout -- the time in seconds to wait attempting to lock the buffer. -1.0 to wait indefinitely and 0 to not wait at all if it can't be acquired immediately. Default is -1.0 (infinite wait).

返回

TRUE if successful, or FALSE on an error.

void GDALARUnlockBuffer(GDALAsyncReaderH hARIO)

Unlock image buffer.

Releases a lock on the image buffer previously taken with LockBuffer().

This is the same as GDALAsyncReader::UnlockBuffer()

参数

hARIO -- handle to async reader.

int GDALGeneralCmdLineProcessor(int nArgc, char ***ppapszArgv, int nOptions)

General utility option processing.

This function is intended to provide a variety of generic commandline options for all GDAL commandline utilities. It takes care of the following commandline options:

—version: report version of GDAL in use. —build: report build info about GDAL in use. —license: report GDAL license info. —formats: report all format drivers configured. —format [format]: report details of one format driver. —optfile filename: expand an option file into the argument list. —config key value: set system configuration option. —debug [on/off/value]: set debug level. —mempreload dir: preload directory contents into /vsimem —pause: Pause for user input (allows time to attach debugger) —locale [locale]: Install a locale using setlocale() (debugging) —help-general: report detailed help on general options.

The argument array is replaced "in place" and should be freed with CSLDestroy() when no longer needed. The typical usage looks something like the following. Note that the formats should be registered so that the —formats and —format options will work properly.

int main( int argc, char ** argv ) { GDALAllRegister();

argc = GDALGeneralCmdLineProcessor( argc, &argv, 0 ); if( argc < 1 ) exit( -argc );

参数

• nArgc -- number of values in the argument list.

• ppapszArgv -- pointer to the argument list array (will be updated in place).

• nOptions -- a or-able combination of GDAL_OF_RASTER and GDAL_OF_VECTOR to determine which drivers should be displayed by &#8212;formats. If set to 0, GDAL_OF_RASTER is assumed.

返回

updated nArgc argument count. Return of 0 requests terminate without error, return of -1 requests exit with error code.

void GDALSwapWords(void *pData, int nWordSize, int nWordCount, int nWordSkip)

Byte swap words in-place.

This function will byte swap a set of 2, 4 or 8 byte words "in place" in a memory array. No assumption is made that the words being swapped are word aligned in memory. Use the CPL_LSB and CPL_MSB macros from cpl_port.h to determine if the current platform is big endian or little endian. Use The macros like CPL_SWAP32() to byte swap single values without the overhead of a function call.

参数

• pData -- pointer to start of data buffer.

• nWordSize -- size of words being swapped in bytes. Normally 2, 4 or 8.

• nWordCount -- the number of words to be swapped in this call.

• nWordSkip -- the byte offset from the start of one word to the start of the next. For packed buffers this is the same as nWordSize.

void GDALSwapWordsEx(void *pData, int nWordSize, size_t nWordCount, int nWordSkip)

Byte swap words in-place.

This function will byte swap a set of 2, 4 or 8 byte words "in place" in a memory array. No assumption is made that the words being swapped are word aligned in memory. Use the CPL_LSB and CPL_MSB macros from cpl_port.h to determine if the current platform is big endian or little endian. Use The macros like CPL_SWAP32() to byte swap single values without the overhead of a function call.

Since

GDAL 2.1

参数

• pData -- pointer to start of data buffer.

• nWordSize -- size of words being swapped in bytes. Normally 2, 4 or 8.

• nWordCount -- the number of words to be swapped in this call.

• nWordSkip -- the byte offset from the start of one word to the start of the next. For packed buffers this is the same as nWordSize.

void GDALCopyWords(const void *pSrcData, GDALDataType eSrcType, int nSrcPixelOffset, void *pDstData, GDALDataType eDstType, int nDstPixelOffset, int nWordCount)

Copy pixel words from buffer to buffer.

参见

GDALCopyWords64()

void GDALCopyWords64(const void *pSrcData, GDALDataType eSrcType, int nSrcPixelOffset, void *pDstData, GDALDataType eDstType, int nDstPixelOffset, GPtrDiff_t nWordCount)

Copy pixel words from buffer to buffer.

This function is used to copy pixel word values from one memory buffer to another, with support for conversion between data types, and differing step factors. The data type conversion is done using the normal GDAL rules. Values assigned to a lower range integer type are clipped. For instance assigning GDT_Int16 values to a GDT_Byte buffer will cause values less the 0 to be set to 0, and values larger than 255 to be set to 255. Assignment from floating point to integer uses default C type casting semantics. Assignment from non-complex to complex will result in the imaginary part being set to zero on output. Assignment from complex to non-complex will result in the complex portion being lost and the real component being preserved (not magnitude!).

No assumptions are made about the source or destination words occurring on word boundaries. It is assumed that all values are in native machine byte order.

备注

When adding a new data type to GDAL, you must do the following to support it properly within the GDALCopyWords function:

1. Add the data type to the switch on eSrcType in GDALCopyWords. This should invoke the appropriate GDALCopyWordsFromT wrapper.

2. Add the data type to the switch on eDstType in GDALCopyWordsFromT. This should call the appropriate GDALCopyWordsT template.

3. If appropriate, overload the appropriate CopyWord template in the above namespace. This will ensure that any conversion issues are handled (cases like the float -> int32 case, where the min/max) values are subject to roundoff error.

参数

• pSrcData -- Pointer to source data to be converted.

• eSrcType -- the source data type (see GDALDataType enum)

• nSrcPixelStride -- Source pixel stride (i.e. distance between 2 words), in bytes

• pDstData -- Pointer to buffer where destination data should go

• eDstType -- the destination data type (see GDALDataType enum)

• nDstPixelStride -- Destination pixel stride (i.e. distance between 2 words), in bytes

• nWordCount -- number of words to be copied

void GDALCopyBits(const GByte *pabySrcData, int nSrcOffset, int nSrcStep, GByte *pabyDstData, int nDstOffset, int nDstStep, int nBitCount, int nStepCount)

Bitwise word copying.

A function for moving sets of partial bytes around. Loosely speaking this is a bitwise analog to GDALCopyWords().

It copies nStepCount "words" where each word is nBitCount bits long. The nSrcStep and nDstStep are the number of bits from the start of one word to the next (same as nBitCount if they are packed). The nSrcOffset and nDstOffset are the offset into the source and destination buffers to start at, also measured in bits.

All bit offsets are assumed to start from the high order bit in a byte (i.e. most significant bit first). Currently this function is not very optimized, but it may be improved for some common cases in the future as needed.

参数

• pabySrcData -- the source data buffer.

• nSrcOffset -- the offset (in bits) in pabySrcData to the start of the first word to copy.

• nSrcStep -- the offset in bits from the start one source word to the start of the next.

• pabyDstData -- the destination data buffer.

• nDstOffset -- the offset (in bits) in pabyDstData to the start of the first word to copy over.

• nDstStep -- the offset in bits from the start one word to the start of the next.

• nBitCount -- the number of bits in a word to be copied.

• nStepCount -- the number of words to copy.

int GDALLoadWorldFile(const char*, double*)

Read ESRI world file.

This function reads an ESRI style world file, and formats a geotransform from its contents.

The world file contains an affine transformation with the parameters in a different order than in a geotransform array.

• geotransform[1] : width of pixel

• geotransform[4] : rotational coefficient, zero for north up images.

• geotransform[2] : rotational coefficient, zero for north up images.

• geotransform[5] : height of pixel (but negative)

• geotransform[0] + 0.5 * geotransform[1] + 0.5 * geotransform[2] : x offset to center of top left pixel.

• geotransform[3] + 0.5 * geotransform[4] + 0.5 * geotransform[5] : y offset to center of top left pixel.

参数

• pszFilename -- the world file name.

• padfGeoTransform -- the six double array into which the geotransformation should be placed.

返回

TRUE on success or FALSE on failure.

int GDALReadWorldFile(const char*, const char*, double*)

Read ESRI world file.

This function reads an ESRI style world file, and formats a geotransform from its contents. It does the same as GDALLoadWorldFile() function, but it will form the filename for the worldfile from the filename of the raster file referred and the suggested extension. If no extension is provided, the code will internally try the unix style and windows style world file extensions (eg. for .tif these would be .tfw and .tifw).

The world file contains an affine transformation with the parameters in a different order than in a geotransform array.

• geotransform[1] : width of pixel

• geotransform[4] : rotational coefficient, zero for north up images.

• geotransform[2] : rotational coefficient, zero for north up images.

• geotransform[5] : height of pixel (but negative)

• geotransform[0] + 0.5 * geotransform[1] + 0.5 * geotransform[2] : x offset to center of top left pixel.

• geotransform[3] + 0.5 * geotransform[4] + 0.5 * geotransform[5] : y offset to center of top left pixel.

参数

• pszBaseFilename -- the target raster file.

• pszExtension -- the extension to use (i.e. "wld") or NULL to derive it from the pszBaseFilename

• padfGeoTransform -- the six double array into which the geotransformation should be placed.

返回

TRUE on success or FALSE on failure.

int GDALWriteWorldFile(const char*, const char*, double*)

Write ESRI world file.

This function writes an ESRI style world file from the passed geotransform.

The world file contains an affine transformation with the parameters in a different order than in a geotransform array.

• geotransform[1] : width of pixel

• geotransform[4] : rotational coefficient, zero for north up images.

• geotransform[2] : rotational coefficient, zero for north up images.

• geotransform[5] : height of pixel (but negative)

• geotransform[0] + 0.5 * geotransform[1] + 0.5 * geotransform[2] : x offset to center of top left pixel.

• geotransform[3] + 0.5 * geotransform[4] + 0.5 * geotransform[5] : y offset to center of top left pixel.

参数

• pszBaseFilename -- the target raster file.

• pszExtension -- the extension to use (i.e. "wld"). Must not be NULL

• padfGeoTransform -- the six double array from which the geotransformation should be read.

返回

TRUE on success or FALSE on failure.

int GDALLoadTabFile(const char*, double*, char**, int*, GDAL_GCP**)

Helper function for translator implementer wanting support for MapInfo .tab files.

参数

• pszFilename -- filename of .tab

• padfGeoTransform -- output geotransform. Must hold 6 doubles.

• ppszWKT -- output pointer to a string that will be allocated with CPLMalloc().

• pnGCPCount -- output pointer to GCP count.

• ppasGCPs -- outputer pointer to an array of GCPs.

返回

TRUE in case of success, FALSE otherwise.

int GDALReadTabFile(const char*, double*, char**, int*, GDAL_GCP**)

Helper function for translator implementer wanting support for MapInfo .tab files.

参数

• pszBaseFilename -- filename whose basename will help building the .tab filename.

• padfGeoTransform -- output geotransform. Must hold 6 doubles.

• ppszWKT -- output pointer to a string that will be allocated with CPLMalloc().

• pnGCPCount -- output pointer to GCP count.

• ppasGCPs -- outputer pointer to an array of GCPs.

返回

TRUE in case of success, FALSE otherwise.

int GDALLoadOziMapFile(const char*, double*, char**, int*, GDAL_GCP**)

Helper function for translator implementer wanting support for OZI .map.

参数

• pszFilename -- filename of .tab file

• padfGeoTransform -- output geotransform. Must hold 6 doubles.

• ppszWKT -- output pointer to a string that will be allocated with CPLMalloc().

• pnGCPCount -- output pointer to GCP count.

• ppasGCPs -- outputer pointer to an array of GCPs.

返回

TRUE in case of success, FALSE otherwise.

int GDALReadOziMapFile(const char*, double*, char**, int*, GDAL_GCP**)

Helper function for translator implementer wanting support for OZI .map.

参数

• pszBaseFilename -- filename whose basename will help building the .map filename.

• padfGeoTransform -- output geotransform. Must hold 6 doubles.

• ppszWKT -- output pointer to a string that will be allocated with CPLMalloc().

• pnGCPCount -- output pointer to GCP count.

• ppasGCPs -- outputer pointer to an array of GCPs.

返回

TRUE in case of success, FALSE otherwise.

const char *GDALDecToDMS(double, const char*, int)

Translate a decimal degrees value to a DMS string with hemisphere.

double GDALPackedDMSToDec(double)

Convert a packed DMS value (DDDMMMSSS.SS) into decimal degrees.

See CPLPackedDMSToDec().

double GDALDecToPackedDMS(double)

Convert decimal degrees into packed DMS value (DDDMMMSSS.SS).

See CPLDecToPackedDMS().

const char *GDALVersionInfo(const char*)

Get runtime version information.

Available pszRequest values:

• "VERSION_NUM": Returns GDAL_VERSION_NUM formatted as a string. i.e. "1170" Note: starting with GDAL 1.10, this string will be longer than 4 characters.

• "RELEASE_DATE": Returns GDAL_RELEASE_DATE formatted as a string. i.e. "20020416".

• "RELEASE_NAME": Returns the GDAL_RELEASE_NAME. ie. "1.1.7"

• "--version": Returns one line version message suitable for use in response to &#8212;version requests. i.e. "GDAL 1.1.7, released 2002/04/16"

• "LICENSE": Returns the content of the LICENSE.TXT file from the GDAL_DATA directory. Before GDAL 1.7.0, the returned string was leaking memory but this is now resolved. So the result should not been freed by the caller.

• "BUILD_INFO": List of NAME=VALUE pairs separated by newlines with information on build time options.

参数

pszRequest -- the type of version info desired, as listed above.

返回

an internal string containing the requested information.

int GDALCheckVersion(int nVersionMajor, int nVersionMinor, const char *pszCallingComponentName)

Return TRUE if GDAL library version at runtime matches nVersionMajor.nVersionMinor.

The purpose of this method is to ensure that calling code will run with the GDAL version it is compiled for. It is primarily intended for external plugins.

参数

• nVersionMajor -- Major version to be tested against

• nVersionMinor -- Minor version to be tested against

• pszCallingComponentName -- If not NULL, in case of version mismatch, the method will issue a failure mentioning the name of the calling component.

返回

TRUE if GDAL library version at runtime matches nVersionMajor.nVersionMinor, FALSE otherwise.

int GDALExtractRPCInfoV2(CSLConstList, GDALRPCInfoV2*)

Extract RPC info from metadata, and apply to an RPCInfo structure.

The inverse of this function is RPCInfoV2ToMD() in alg/gdal_rpc.cpp

参数

• papszMD -- Dictionary of metadata representing RPC

• psRPC -- (output) Pointer to structure to hold the RPC values.

返回

TRUE in case of success. FALSE in case of failure.

GDALColorTableH GDALCreateColorTable(GDALPaletteInterp)

Construct a new color table.

This function is the same as the C++ method GDALColorTable::GDALColorTable()

void GDALDestroyColorTable(GDALColorTableH)

Destroys a color table.

This function is the same as the C++ method GDALColorTable::~GDALColorTable()

GDALColorTableH GDALCloneColorTable(GDALColorTableH)

Make a copy of a color table.

This function is the same as the C++ method GDALColorTable::Clone()

GDALPaletteInterp GDALGetPaletteInterpretation(GDALColorTableH)

Fetch palette interpretation.

This function is the same as the C++ method GDALColorTable::GetPaletteInterpretation()

int GDALGetColorEntryCount(GDALColorTableH)

Get number of color entries in table.

This function is the same as the C++ method GDALColorTable::GetColorEntryCount()

const GDALColorEntry *GDALGetColorEntry(GDALColorTableH, int)

Fetch a color entry from table.

This function is the same as the C++ method GDALColorTable::GetColorEntry()

int GDALGetColorEntryAsRGB(GDALColorTableH, int, GDALColorEntry*)

Fetch a table entry in RGB format.

This function is the same as the C++ method GDALColorTable::GetColorEntryAsRGB().

void GDALSetColorEntry(GDALColorTableH, int, const GDALColorEntry*)

Set entry in color table.

This function is the same as the C++ method GDALColorTable::SetColorEntry()

void GDALCreateColorRamp(GDALColorTableH hTable, int nStartIndex, const GDALColorEntry *psStartColor, int nEndIndex, const GDALColorEntry *psEndColor)

Create color ramp.

This function is the same as the C++ method GDALColorTable::CreateColorRamp()

GDALRasterAttributeTableH GDALCreateRasterAttributeTable(void)

Construct empty table.

This function is the same as the C++ method GDALDefaultRasterAttributeTable::GDALDefaultRasterAttributeTable()

void GDALDestroyRasterAttributeTable(GDALRasterAttributeTableH)

Destroys a RAT.

This function is the same as the C++ method GDALRasterAttributeTable::~GDALRasterAttributeTable()

int GDALRATGetColumnCount(GDALRasterAttributeTableH)

Fetch table column count.

This function is the same as the C++ method GDALRasterAttributeTable::GetColumnCount()

const char *GDALRATGetNameOfCol(GDALRasterAttributeTableH, int)

Fetch name of indicated column.

This function is the same as the C++ method GDALRasterAttributeTable::GetNameOfCol()

参数

• hRAT -- RAT handle.

• iCol -- column index.

返回

name.

GDALRATFieldUsage GDALRATGetUsageOfCol(GDALRasterAttributeTableH, int)

Fetch column usage value.

This function is the same as the C++ method GDALRasterAttributeTable::GetUsageOfCol()

参数

• hRAT -- RAT handle.

• iCol -- column index.

返回

usage.

GDALRATFieldType GDALRATGetTypeOfCol(GDALRasterAttributeTableH, int)

Fetch column type.

This function is the same as the C++ method GDALRasterAttributeTable::GetTypeOfCol()

参数

• hRAT -- RAT handle.

• iCol -- column index.

返回

type.

int GDALRATGetColOfUsage(GDALRasterAttributeTableH, GDALRATFieldUsage)

Fetch column index for given usage.

This function is the same as the C++ method GDALRasterAttributeTable::GetColOfUsage()

int GDALRATGetRowCount(GDALRasterAttributeTableH)

Fetch row count.

This function is the same as the C++ method GDALRasterAttributeTable::GetRowCount()

const char *GDALRATGetValueAsString(GDALRasterAttributeTableH, int, int)

Fetch field value as a string.

This function is the same as the C++ method GDALRasterAttributeTable::GetValueAsString()

int GDALRATGetValueAsInt(GDALRasterAttributeTableH, int, int)

Fetch field value as a integer.

This function is the same as the C++ method GDALRasterAttributeTable::GetValueAsInt()

double GDALRATGetValueAsDouble(GDALRasterAttributeTableH, int, int)

Fetch field value as a double.

This function is the same as the C++ method GDALRasterAttributeTable::GetValueAsDouble()

void GDALRATSetValueAsString(GDALRasterAttributeTableH, int, int, const char*)

Set field value from string.

This function is the same as the C++ method GDALRasterAttributeTable::SetValue()

参数

• hRAT -- RAT handle.

• iRow -- row index.

• iField -- field index.

• pszValue -- value.

void GDALRATSetValueAsInt(GDALRasterAttributeTableH, int, int, int)

Set field value from integer.

This function is the same as the C++ method GDALRasterAttributeTable::SetValue()

void GDALRATSetValueAsDouble(GDALRasterAttributeTableH, int, int, double)

Set field value from double.

This function is the same as the C++ method GDALRasterAttributeTable::SetValue()

int GDALRATChangesAreWrittenToFile(GDALRasterAttributeTableH hRAT)

Determine whether changes made to this RAT are reflected directly in the dataset.

This function is the same as the C++ method GDALRasterAttributeTable::ChangesAreWrittenToFile()

CPLErr GDALRATValuesIOAsDouble(GDALRasterAttributeTableH hRAT, GDALRWFlag eRWFlag, int iField, int iStartRow, int iLength, double *pdfData)

Read or Write a block of doubles to/from the Attribute Table.

This function is the same as the C++ method GDALRasterAttributeTable::ValuesIO()

CPLErr GDALRATValuesIOAsInteger(GDALRasterAttributeTableH hRAT, GDALRWFlag eRWFlag, int iField, int iStartRow, int iLength, int *pnData)

Read or Write a block of ints to/from the Attribute Table.

This function is the same as the C++ method GDALRasterAttributeTable::ValuesIO()

CPLErr GDALRATValuesIOAsString(GDALRasterAttributeTableH hRAT, GDALRWFlag eRWFlag, int iField, int iStartRow, int iLength, CSLConstList papszStrList)

Read or Write a block of strings to/from the Attribute Table.

This function is the same as the C++ method GDALRasterAttributeTable::ValuesIO()

void GDALRATSetRowCount(GDALRasterAttributeTableH, int)

Set row count.

This function is the same as the C++ method GDALRasterAttributeTable::SetRowCount()

参数

• hRAT -- RAT handle.

• nNewCount -- the new number of rows.

CPLErr GDALRATCreateColumn(GDALRasterAttributeTableH, const char*, GDALRATFieldType, GDALRATFieldUsage)

Create new column.

This function is the same as the C++ method GDALRasterAttributeTable::CreateColumn()

CPLErr GDALRATSetLinearBinning(GDALRasterAttributeTableH, double, double)

Set linear binning information.

This function is the same as the C++ method GDALRasterAttributeTable::SetLinearBinning()

int GDALRATGetLinearBinning(GDALRasterAttributeTableH, double*, double*)

Get linear binning information.

This function is the same as the C++ method GDALRasterAttributeTable::GetLinearBinning()

CPLErr GDALRATSetTableType(GDALRasterAttributeTableH hRAT, const GDALRATTableType eInTableType)

Set RAT Table Type.

This function is the same as the C++ method GDALRasterAttributeTable::SetTableType()

Since

GDAL 2.4

GDALRATTableType GDALRATGetTableType(GDALRasterAttributeTableH hRAT)

Get Rat Table Type.

This function is the same as the C++ method GDALRasterAttributeTable::GetTableType()

Since

GDAL 2.4

CPLErr GDALRATInitializeFromColorTable(GDALRasterAttributeTableH, GDALColorTableH)

Initialize from color table.

This function is the same as the C++ method GDALRasterAttributeTable::InitializeFromColorTable()

GDALColorTableH GDALRATTranslateToColorTable(GDALRasterAttributeTableH, int nEntryCount)

Translate to a color table.

This function is the same as the C++ method GDALRasterAttributeTable::TranslateToColorTable()

void GDALRATDumpReadable(GDALRasterAttributeTableH, FILE*)

Dump RAT in readable form.

This function is the same as the C++ method GDALRasterAttributeTable::DumpReadable()

GDALRasterAttributeTableH GDALRATClone(const GDALRasterAttributeTableH)

Copy Raster Attribute Table.

This function is the same as the C++ method GDALRasterAttributeTable::Clone()

void *GDALRATSerializeJSON(GDALRasterAttributeTableH)

Serialize Raster Attribute Table in Json format.

This function is the same as the C++ method GDALRasterAttributeTable::SerializeJSON()

int GDALRATGetRowOfValue(GDALRasterAttributeTableH, double)

Get row for pixel value.

This function is the same as the C++ method GDALRasterAttributeTable::GetRowOfValue()

void GDALRATRemoveStatistics(GDALRasterAttributeTableH)

Remove Statistics from RAT.

This function is the same as the C++ method GDALRasterAttributeTable::RemoveStatistics()

Since

GDAL 2.4

void GDALSetCacheMax(int nBytes)

Set maximum cache memory.

This function sets the maximum amount of memory that GDAL is permitted to use for GDALRasterBlock caching. The unit of the value is bytes.

The maximum value is 2GB, due to the use of a signed 32 bit integer. Use GDALSetCacheMax64() to be able to set a higher value.

参数

nNewSizeInBytes -- the maximum number of bytes for caching.

int GDALGetCacheMax(void)

Get maximum cache memory.

Gets the maximum amount of memory available to the GDALRasterBlock caching system for caching GDAL read/write imagery.

The first type this function is called, it will read the GDAL_CACHEMAX configuration option to initialize the maximum cache memory. Starting with GDAL 2.1, the value can be expressed as x% of the usable physical RAM (which may potentially be used by other processes). Otherwise it is expected to be a value in MB.

This function cannot return a value higher than 2 GB. Use GDALGetCacheMax64() to get a non-truncated value.

返回

maximum in bytes.

int GDALGetCacheUsed(void)

Get cache memory used.

返回

the number of bytes of memory currently in use by the GDALRasterBlock memory caching.

void GDALSetCacheMax64(GIntBig nBytes)

Set maximum cache memory.

This function sets the maximum amount of memory that GDAL is permitted to use for GDALRasterBlock caching. The unit of the value is bytes.

Note: On 32 bit platforms, the maximum amount of memory that can be addressed by a process might be 2 GB or 3 GB, depending on the operating system capabilities. This function will not make any attempt to check the consistency of the passed value with the effective capabilities of the OS.

Since

GDAL 1.8.0

参数

nNewSizeInBytes -- the maximum number of bytes for caching.

GIntBig GDALGetCacheMax64(void)

Get maximum cache memory.

Gets the maximum amount of memory available to the GDALRasterBlock caching system for caching GDAL read/write imagery.

The first type this function is called, it will read the GDAL_CACHEMAX configuration option to initialize the maximum cache memory. Starting with GDAL 2.1, the value can be expressed as x% of the usable physical RAM (which may potentially be used by other processes). Otherwise it is expected to be a value in MB.

Since

GDAL 1.8.0

返回

maximum in bytes.

GIntBig GDALGetCacheUsed64(void)

Get cache memory used.

Since

GDAL 1.8.0

返回

the number of bytes of memory currently in use by the GDALRasterBlock memory caching.

int GDALFlushCacheBlock(void)

Try to flush one cached raster block.

This function will search the first unlocked raster block and will flush it to release the associated memory.

返回

TRUE if one block was flushed, FALSE if there are no cached blocks or if they are currently locked.

CPLVirtualMem *GDALDatasetGetVirtualMem(GDALDatasetH hDS, GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize, int nYSize, int nBufXSize, int nBufYSize, GDALDataType eBufType, int nBandCount, int *panBandMap, int nPixelSpace, GIntBig nLineSpace, GIntBig nBandSpace, size_t nCacheSize, size_t nPageSizeHint, int bSingleThreadUsage, CSLConstList papszOptions)

Create a CPLVirtualMem object from a GDAL dataset object.

Only supported on Linux for now.

This method allows creating a virtual memory object for a region of one or more GDALRasterBands from this dataset. The content of the virtual memory object is automatically filled from dataset content when a virtual memory page is first accessed, and it is released (or flushed in case of a "dirty" page) when the cache size limit has been reached.

The pointer to access the virtual memory object is obtained with CPLVirtualMemGetAddr(). It remains valid until CPLVirtualMemFree() is called. CPLVirtualMemFree() must be called before the dataset object is destroyed.

If p is such a pointer and base_type the C type matching eBufType, for default values of spacing parameters, the element of image coordinates (x, y) (relative to xOff, yOff) for band b can be accessed with ((base_type*)p)[x + y * nBufXSize + (b-1)*nBufXSize*nBufYSize].

Note that the mechanism used to transparently fill memory pages when they are accessed is the same (but in a controlled way) than what occurs when a memory error occurs in a program. Debugging software will generally interrupt program execution when that happens. If needed, CPLVirtualMemPin() can be used to avoid that by ensuring memory pages are allocated before being accessed.

The size of the region that can be mapped as a virtual memory object depends on hardware and operating system limitations. On Linux AMD64 platforms, the maximum value is 128 TB. On Linux x86 platforms, the maximum value is 2 GB.

Data type translation is automatically done if the data type (eBufType) of the buffer is different than that of the GDALRasterBand.

Image decimation / replication is currently not supported, i.e. if the size of the region being accessed (nXSize x nYSize) is different from the buffer size (nBufXSize x nBufYSize).

The nPixelSpace, nLineSpace and nBandSpace parameters allow reading into or writing from various organization of buffers. Arbitrary values for the spacing parameters are not supported. Those values must be multiple of the size of thebuffer data type, and must be either band sequential organization (typically nPixelSpace = GDALGetDataTypeSizeBytes(eBufType), nLineSpace = nPixelSpace * nBufXSize, nBandSpace = nLineSpace * nBufYSize), or pixel-interleaved organization (typically nPixelSpace = nBandSpace * nBandCount, nLineSpace = nPixelSpace * nBufXSize, nBandSpace = GDALGetDataTypeSizeBytes(eBufType))

Since

GDAL 1.11

参数

• hDS -- Dataset object

• eRWFlag -- Either GF_Read to read a region of data, or GF_Write to write a region of data.

• nXOff -- The pixel offset to the top left corner of the region of the band to be accessed. This would be zero to start from the left side.

• nYOff -- The line offset to the top left corner of the region of the band to be accessed. This would be zero to start from the top.

• nXSize -- The width of the region of the band to be accessed in pixels.

• nYSize -- The height of the region of the band to be accessed in lines.

• nBufXSize -- the width of the buffer image into which the desired region is to be read, or from which it is to be written.

• nBufYSize -- the height of the buffer image into which the desired region is to be read, or from which it is to be written.

• eBufType -- the type of the pixel values in the data buffer. The pixel values will automatically be translated to/from the GDALRasterBand data type as needed.

• nBandCount -- the number of bands being read or written.

• panBandMap -- the list of nBandCount band numbers being read/written. Note band numbers are 1 based. This may be NULL to select the first nBandCount bands.

• nPixelSpace -- The byte offset from the start of one pixel value in the buffer to the start of the next pixel value within a scanline. If defaulted (0) the size of the datatype eBufType is used.

• nLineSpace -- The byte offset from the start of one scanline in the buffer to the start of the next. If defaulted (0) the size of the datatype eBufType * nBufXSize is used.

• nBandSpace -- the byte offset from the start of one bands data to the start of the next. If defaulted (0) the value will be nLineSpace * nBufYSize implying band sequential organization of the data buffer.

• nCacheSize -- size in bytes of the maximum memory that will be really allocated (must ideally fit into RAM)

• nPageSizeHint -- hint for the page size. Must be a multiple of the system page size, returned by CPLGetPageSize(). Minimum value is generally 4096. Might be set to 0 to let the function determine a default page size.

• bSingleThreadUsage -- set to TRUE if there will be no concurrent threads that will access the virtual memory mapping. This can optimize performance a bit. If set to FALSE, CPLVirtualMemDeclareThread() must be called.

• papszOptions -- NULL terminated list of options. Unused for now.

返回

a virtual memory object that must be freed by CPLVirtualMemFree(), or NULL in case of failure.

CPLVirtualMem *GDALRasterBandGetVirtualMem(GDALRasterBandH hBand, GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize, int nYSize, int nBufXSize, int nBufYSize, GDALDataType eBufType, int nPixelSpace, GIntBig nLineSpace, size_t nCacheSize, size_t nPageSizeHint, int bSingleThreadUsage, CSLConstList papszOptions)

Create a CPLVirtualMem object from a GDAL raster band object.

Only supported on Linux for now.

This method allows creating a virtual memory object for a region of a GDALRasterBand. The content of the virtual memory object is automatically filled from dataset content when a virtual memory page is first accessed, and it is released (or flushed in case of a "dirty" page) when the cache size limit has been reached.

The pointer to access the virtual memory object is obtained with CPLVirtualMemGetAddr(). It remains valid until CPLVirtualMemFree() is called. CPLVirtualMemFree() must be called before the raster band object is destroyed.

If p is such a pointer and base_type the C type matching eBufType, for values of spacing parameters, the element of image coordinates (x, y) default (relative to xOff, yOff) can be accessed with ((base_type*)p)[x + y * nBufXSize].

Note that the mechanism used to transparently fill memory pages when they are accessed is the same (but in a controlled way) than what occurs when a memory error occurs in a program. Debugging software will generally interrupt program execution when that happens. If needed, CPLVirtualMemPin() can be used to avoid that by ensuring memory pages are allocated before being accessed.

The size of the region that can be mapped as a virtual memory object depends on hardware and operating system limitations. On Linux AMD64 platforms, the maximum value is 128 TB. On Linux x86 platforms, the maximum value is 2 GB.

Data type translation is automatically done if the data type (eBufType) of the buffer is different than that of the GDALRasterBand.

Image decimation / replication is currently not supported, i.e. if the size of the region being accessed (nXSize x nYSize) is different from the buffer size (nBufXSize x nBufYSize).

The nPixelSpace and nLineSpace parameters allow reading into or writing from various organization of buffers. Arbitrary values for the spacing parameters are not supported. Those values must be multiple of the size of the buffer data type and must be such that nLineSpace >= nPixelSpace * nBufXSize.

Since

GDAL 1.11

参数

• hBand -- Rasterband object

• eRWFlag -- Either GF_Read to read a region of data, or GF_Write to write a region of data.

• nXOff -- The pixel offset to the top left corner of the region of the band to be accessed. This would be zero to start from the left side.

• nYOff -- The line offset to the top left corner of the region of the band to be accessed. This would be zero to start from the top.

• nXSize -- The width of the region of the band to be accessed in pixels.

• nYSize -- The height of the region of the band to be accessed in lines.

• nBufXSize -- the width of the buffer image into which the desired region is to be read, or from which it is to be written.

• nBufYSize -- the height of the buffer image into which the desired region is to be read, or from which it is to be written.

• eBufType -- the type of the pixel values in the data buffer. The pixel values will automatically be translated to/from the GDALRasterBand data type as needed.

• nPixelSpace -- The byte offset from the start of one pixel value in the buffer to the start of the next pixel value within a scanline. If defaulted (0) the size of the datatype eBufType is used.

• nLineSpace -- The byte offset from the start of one scanline in the buffer to the start of the next. If defaulted (0) the size of the datatype eBufType * nBufXSize is used.

• nCacheSize -- size in bytes of the maximum memory that will be really allocated (must ideally fit into RAM)

• nPageSizeHint -- hint for the page size. Must be a multiple of the system page size, returned by CPLGetPageSize(). Minimum value is generally 4096. Might be set to 0 to let the function determine a default page size.

• bSingleThreadUsage -- set to TRUE if there will be no concurrent threads that will access the virtual memory mapping. This can optimize performance a bit. If set to FALSE, CPLVirtualMemDeclareThread() must be called.

• papszOptions -- NULL terminated list of options. Unused for now.

返回

a virtual memory object that must be freed by CPLVirtualMemFree(), or NULL in case of failure.

CPLVirtualMem *GDALGetVirtualMemAuto(GDALRasterBandH hBand, GDALRWFlag eRWFlag, int *pnPixelSpace, GIntBig *pnLineSpace, CSLConstList papszOptions)

Create a CPLVirtualMem object from a GDAL raster band object.

参见

GDALRasterBand::GetVirtualMemAuto()

CPLVirtualMem *GDALDatasetGetTiledVirtualMem(GDALDatasetH hDS, GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize, int nYSize, int nTileXSize, int nTileYSize, GDALDataType eBufType, int nBandCount, int *panBandMap, GDALTileOrganization eTileOrganization, size_t nCacheSize, int bSingleThreadUsage, CSLConstList papszOptions)

Create a CPLVirtualMem object from a GDAL dataset object, with tiling organization.

Only supported on Linux for now.

This method allows creating a virtual memory object for a region of one or more GDALRasterBands from this dataset. The content of the virtual memory object is automatically filled from dataset content when a virtual memory page is first accessed, and it is released (or flushed in case of a "dirty" page) when the cache size limit has been reached.

Contrary to GDALDatasetGetVirtualMem(), pixels will be organized by tiles instead of scanlines. Different ways of organizing pixel within/across tiles can be selected with the eTileOrganization parameter.

If nXSize is not a multiple of nTileXSize or nYSize is not a multiple of nTileYSize, partial tiles will exists at the right and/or bottom of the region of interest. Those partial tiles will also have nTileXSize * nTileYSize dimension, with padding pixels.

The pointer to access the virtual memory object is obtained with CPLVirtualMemGetAddr(). It remains valid until CPLVirtualMemFree() is called. CPLVirtualMemFree() must be called before the dataset object is destroyed.

If p is such a pointer and base_type the C type matching eBufType, for default values of spacing parameters, the element of image coordinates (x, y) (relative to xOff, yOff) for band b can be accessed with:

• for eTileOrganization = GTO_TIP, ((base_type*)p)[tile_number(x,y)*nBandCount*tile_size + offset_in_tile(x,y)*nBandCount + (b-1)].

• for eTileOrganization = GTO_BIT, ((base_type*)p)[(tile_number(x,y)*nBandCount + (b-1)) * tile_size + offset_in_tile(x,y)].

• for eTileOrganization = GTO_BSQ, ((base_type*)p)[(tile_number(x,y) + (b-1)*nTilesCount) * tile_size + offset_in_tile(x,y)].

where nTilesPerRow = ceil(nXSize / nTileXSize) nTilesPerCol = ceil(nYSize / nTileYSize) nTilesCount = nTilesPerRow * nTilesPerCol tile_number(x,y) = (y / nTileYSize) * nTilesPerRow + (x / nTileXSize) offset_in_tile(x,y) = (y % nTileYSize) * nTileXSize + (x % nTileXSize) tile_size = nTileXSize * nTileYSize

Note that for a single band request, all tile organizations are equivalent.

Note that the mechanism used to transparently fill memory pages when they are accessed is the same (but in a controlled way) than what occurs when a memory error occurs in a program. Debugging software will generally interrupt program execution when that happens. If needed, CPLVirtualMemPin() can be used to avoid that by ensuring memory pages are allocated before being accessed.

The size of the region that can be mapped as a virtual memory object depends on hardware and operating system limitations. On Linux AMD64 platforms, the maximum value is 128 TB. On Linux x86 platforms, the maximum value is 2 GB.

Data type translation is automatically done if the data type (eBufType) of the buffer is different than that of the GDALRasterBand.

Since

GDAL 1.11

参数

• hDS -- Dataset object

• eRWFlag -- Either GF_Read to read a region of data, or GF_Write to write a region of data.

• nXOff -- The pixel offset to the top left corner of the region of the band to be accessed. This would be zero to start from the left side.

• nYOff -- The line offset to the top left corner of the region of the band to be accessed. This would be zero to start from the top.

• nXSize -- The width of the region of the band to be accessed in pixels.

• nYSize -- The height of the region of the band to be accessed in lines.

• nTileXSize -- the width of the tiles.

• nTileYSize -- the height of the tiles.

• eBufType -- the type of the pixel values in the data buffer. The pixel values will automatically be translated to/from the GDALRasterBand data type as needed.

• nBandCount -- the number of bands being read or written.

• panBandMap -- the list of nBandCount band numbers being read/written. Note band numbers are 1 based. This may be NULL to select the first nBandCount bands.

• eTileOrganization -- tile organization.

• nCacheSize -- size in bytes of the maximum memory that will be really allocated (must ideally fit into RAM)

• bSingleThreadUsage -- set to TRUE if there will be no concurrent threads that will access the virtual memory mapping. This can optimize performance a bit. If set to FALSE, CPLVirtualMemDeclareThread() must be called.

• papszOptions -- NULL terminated list of options. Unused for now.

返回

a virtual memory object that must be freed by CPLVirtualMemFree(), or NULL in case of failure.

CPLVirtualMem *GDALRasterBandGetTiledVirtualMem(GDALRasterBandH hBand, GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize, int nYSize, int nTileXSize, int nTileYSize, GDALDataType eBufType, size_t nCacheSize, int bSingleThreadUsage, CSLConstList papszOptions)

Create a CPLVirtualMem object from a GDAL rasterband object, with tiling organization.

Only supported on Linux for now.

This method allows creating a virtual memory object for a region of one GDALRasterBand. The content of the virtual memory object is automatically filled from dataset content when a virtual memory page is first accessed, and it is released (or flushed in case of a "dirty" page) when the cache size limit has been reached.

Contrary to GDALDatasetGetVirtualMem(), pixels will be organized by tiles instead of scanlines.

If nXSize is not a multiple of nTileXSize or nYSize is not a multiple of nTileYSize, partial tiles will exists at the right and/or bottom of the region of interest. Those partial tiles will also have nTileXSize * nTileYSize dimension, with padding pixels.

The pointer to access the virtual memory object is obtained with CPLVirtualMemGetAddr(). It remains valid until CPLVirtualMemFree() is called. CPLVirtualMemFree() must be called before the raster band object is destroyed.

If p is such a pointer and base_type the C type matching eBufType, for default values of spacing parameters, the element of image coordinates (x, y) (relative to xOff, yOff) can be accessed with: ((base_type*)p)[tile_number(x,y)*tile_size + offset_in_tile(x,y)].

where nTilesPerRow = ceil(nXSize / nTileXSize) nTilesCount = nTilesPerRow * nTilesPerCol tile_number(x,y) = (y / nTileYSize) * nTilesPerRow + (x / nTileXSize) offset_in_tile(x,y) = (y % nTileYSize) * nTileXSize + (x % nTileXSize) tile_size = nTileXSize * nTileYSize

Note that the mechanism used to transparently fill memory pages when they are accessed is the same (but in a controlled way) than what occurs when a memory error occurs in a program. Debugging software will generally interrupt program execution when that happens. If needed, CPLVirtualMemPin() can be used to avoid that by ensuring memory pages are allocated before being accessed.

The size of the region that can be mapped as a virtual memory object depends on hardware and operating system limitations. On Linux AMD64 platforms, the maximum value is 128 TB. On Linux x86 platforms, the maximum value is 2 GB.

Data type translation is automatically done if the data type (eBufType) of the buffer is different than that of the GDALRasterBand.

Since

GDAL 1.11

参数

• hBand -- Rasterband object

• eRWFlag -- Either GF_Read to read a region of data, or GF_Write to write a region of data.

• nXOff -- The pixel offset to the top left corner of the region of the band to be accessed. This would be zero to start from the left side.

• nYOff -- The line offset to the top left corner of the region of the band to be accessed. This would be zero to start from the top.

• nXSize -- The width of the region of the band to be accessed in pixels.

• nYSize -- The height of the region of the band to be accessed in lines.

• nTileXSize -- the width of the tiles.

• nTileYSize -- the height of the tiles.

• eBufType -- the type of the pixel values in the data buffer. The pixel values will automatically be translated to/from the GDALRasterBand data type as needed.

• nCacheSize -- size in bytes of the maximum memory that will be really allocated (must ideally fit into RAM)

• bSingleThreadUsage -- set to TRUE if there will be no concurrent threads that will access the virtual memory mapping. This can optimize performance a bit. If set to FALSE, CPLVirtualMemDeclareThread() must be called.

• papszOptions -- NULL terminated list of options. Unused for now.

返回

a virtual memory object that must be freed by CPLVirtualMemFree(), or NULL in case of failure.

GDALDatasetH GDALCreatePansharpenedVRT(const char *pszXML, GDALRasterBandH hPanchroBand, int nInputSpectralBands, GDALRasterBandH *pahInputSpectralBands)

Create a virtual pansharpened dataset.

This function will create a virtual pansharpened dataset.

Note that no reference will be taken on the passed bands. Consequently, they or their dataset to which they belong to must be kept open until this virtual pansharpened dataset is closed.

The returned dataset will have no associated filename for itself. If you want to write the virtual dataset description to a file, use the GDALSetDescription() function (or SetDescription() method) on the dataset to assign a filename before it is closed.

Since

GDAL 2.1

参数

• pszXML -- Pansharpened VRT XML where <SpectralBand> elements have no explicit SourceFilename and SourceBand. The spectral bands in the XML will be assigned the successive values of the pahInputSpectralBands array. Must not be NULL.

• hPanchroBand -- Panchromatic band. Must not be NULL.

• nInputSpectralBands -- Number of input spectral bands. Must be greater than zero.

• pahInputSpectralBands -- Array of nInputSpectralBands spectral bands.

返回

NULL on failure, or a new virtual dataset handle on success to be closed with GDALClose().

CPLXMLNode *GDALGetJPEG2000Structure(const char *pszFilename, CSLConstList papszOptions)

Dump the structure of a JPEG2000 file as a XML tree.

Since

GDAL 2.0

参数

• pszFilename -- filename.

• papszOptions -- NULL terminated list of options, or NULL. Allowed options are BINARY_CONTENT=YES, TEXT_CONTENT=YES, CODESTREAM=YES, ALL=YES.

返回

XML tree (to be freed with CPLDestroyXMLNode()) or NULL in case of error

GDALDatasetH GDALCreateMultiDimensional(GDALDriverH hDriver, const char *pszName, CSLConstList papszRootGroupOptions, CSLConstList papszOptions)

Create a new multidimensional dataset with this driver.

This is the same as the C++ method GDALDriver::CreateMultiDimensional().

GDALExtendedDataTypeH GDALExtendedDataTypeCreate(GDALDataType eType)

Return a new GDALExtendedDataType of class GEDTC_NUMERIC.

This is the same as the C++ method GDALExtendedDataType::Create()

The returned handle should be freed with GDALExtendedDataTypeRelease().

参数

eType -- Numeric data type.

返回

a new GDALExtendedDataTypeH handle, or nullptr.

GDALExtendedDataTypeH GDALExtendedDataTypeCreateString(size_t nMaxStringLength)

Return a new GDALExtendedDataType of class GEDTC_STRING.

This is the same as the C++ method GDALExtendedDataType::CreateString()

The returned handle should be freed with GDALExtendedDataTypeRelease().

返回

a new GDALExtendedDataTypeH handle, or nullptr.

GDALExtendedDataTypeH GDALExtendedDataTypeCreateStringEx(size_t nMaxStringLength, GDALExtendedDataTypeSubType eSubType)

Return a new GDALExtendedDataType of class GEDTC_STRING.

This is the same as the C++ method GDALExtendedDataType::CreateString()

The returned handle should be freed with GDALExtendedDataTypeRelease().

Since

GDAL 3.4

返回

a new GDALExtendedDataTypeH handle, or nullptr.

GDALExtendedDataTypeH GDALExtendedDataTypeCreateCompound(const char *pszName, size_t nTotalSize, size_t nComponents, const GDALEDTComponentH *comps)

Return a new GDALExtendedDataType of class GEDTC_COMPOUND.

This is the same as the C++ method GDALExtendedDataType::Create(const std::string&, size_t, std::vector<std::unique_ptr<GDALEDTComponent>>&&)

The returned handle should be freed with GDALExtendedDataTypeRelease().

参数

• pszName -- Type name.

• nTotalSize -- Total size of the type in bytes. Should be large enough to store all components.

• nComponents -- Number of components in comps array.

• comps -- Components.

返回

a new GDALExtendedDataTypeH handle, or nullptr.

void GDALExtendedDataTypeRelease(GDALExtendedDataTypeH hEDT)

Release the GDAL in-memory object associated with a GDALExtendedDataTypeH.

Note: when applied on a object coming from a driver, this does not destroy the object in the file, database, etc...

const char *GDALExtendedDataTypeGetName(GDALExtendedDataTypeH hEDT)

Return type name.

This is the same as the C++ method GDALExtendedDataType::GetName()

GDALExtendedDataTypeClass GDALExtendedDataTypeGetClass(GDALExtendedDataTypeH hEDT)

Return type class.

This is the same as the C++ method GDALExtendedDataType::GetClass()

GDALDataType GDALExtendedDataTypeGetNumericDataType(GDALExtendedDataTypeH hEDT)

Return numeric data type (only valid when GetClass() == GEDTC_NUMERIC)

This is the same as the C++ method GDALExtendedDataType::GetNumericDataType()

size_t GDALExtendedDataTypeGetSize(GDALExtendedDataTypeH hEDT)

Return data type size in bytes.

This is the same as the C++ method GDALExtendedDataType::GetSize()

size_t GDALExtendedDataTypeGetMaxStringLength(GDALExtendedDataTypeH hEDT)

Return the maximum length of a string in bytes.

0 indicates unknown/unlimited string.

This is the same as the C++ method GDALExtendedDataType::GetMaxStringLength()

GDALEDTComponentH *GDALExtendedDataTypeGetComponents(GDALExtendedDataTypeH hEDT, size_t *pnCount)

Return the components of the data type (only valid when GetClass() == GEDTC_COMPOUND)

The returned array and its content must be freed with GDALExtendedDataTypeFreeComponents(). If only the array itself needs to be freed, CPLFree() should be called (and GDALExtendedDataTypeRelease() on individual array members).

This is the same as the C++ method GDALExtendedDataType::GetComponents()

参数

• hEDT -- Data type

• pnCount -- Pointer to the number of values returned. Must NOT be NULL.

返回

an array of *pnCount components.

void GDALExtendedDataTypeFreeComponents(GDALEDTComponentH *components, size_t nCount)

Free the return of GDALExtendedDataTypeGetComponents().

参数

• components -- return value of GDALExtendedDataTypeGetComponents()

• nCount -- *pnCount value returned by GDALExtendedDataTypeGetComponents()

int GDALExtendedDataTypeCanConvertTo(GDALExtendedDataTypeH hSourceEDT, GDALExtendedDataTypeH hTargetEDT)

Return whether this data type can be converted to the other one.

This is the same as the C function GDALExtendedDataType::CanConvertTo()

参数

• hSourceEDT -- Source data type for the conversion being considered.

• hTargetEDT -- Target data type for the conversion being considered.

返回

TRUE if hSourceEDT can be convert to hTargetEDT. FALSE otherwise.

int GDALExtendedDataTypeEquals(GDALExtendedDataTypeH hFirstEDT, GDALExtendedDataTypeH hSecondEDT)

Return whether this data type is equal to another one.

This is the same as the C++ method GDALExtendedDataType::operator==()

参数

• hFirstEDT -- First data type.

• hSecondEDT -- Second data type.

返回

TRUE if they are equal. FALSE otherwise.

GDALExtendedDataTypeSubType GDALExtendedDataTypeGetSubType(GDALExtendedDataTypeH hEDT)

Return the subtype of a type.

This is the same as the C++ method GDALExtendedDataType::GetSubType()

Since

3.4

参数

hEDT -- Data type.

返回

subtype.

GDALEDTComponentH GDALEDTComponentCreate(const char *pszName, size_t nOffset, GDALExtendedDataTypeH hType)

Create a new GDALEDTComponent.

The returned value must be freed with GDALEDTComponentRelease().

This is the same as the C++ constructor GDALEDTComponent::GDALEDTComponent().

void GDALEDTComponentRelease(GDALEDTComponentH hComp)

Release the GDAL in-memory object associated with a GDALEDTComponentH.

Note: when applied on a object coming from a driver, this does not destroy the object in the file, database, etc...

const char *GDALEDTComponentGetName(GDALEDTComponentH hComp)

Return the name.

The returned pointer is valid until hComp is released.

This is the same as the C++ method GDALEDTComponent::GetName().

size_t GDALEDTComponentGetOffset(GDALEDTComponentH hComp)

Return the offset (in bytes) of the component in the compound data type.

This is the same as the C++ method GDALEDTComponent::GetOffset().

GDALExtendedDataTypeH GDALEDTComponentGetType(GDALEDTComponentH hComp)

Return the data type of the component.

This is the same as the C++ method GDALEDTComponent::GetType().

GDALGroupH GDALDatasetGetRootGroup(GDALDatasetH hDS)

Return the root GDALGroup of this dataset.

Only valid for multidimensional datasets.

The returned value must be freed with GDALGroupRelease().

This is the same as the C++ method GDALDataset::GetRootGroup().

Since

GDAL 3.1

void GDALGroupRelease(GDALGroupH hGroup)

Release the GDAL in-memory object associated with a GDALGroupH.

Note: when applied on a object coming from a driver, this does not destroy the object in the file, database, etc...

const char *GDALGroupGetName(GDALGroupH hGroup)

Return the name of the group.

The returned pointer is valid until hGroup is released.

This is the same as the C++ method GDALGroup::GetName().

const char *GDALGroupGetFullName(GDALGroupH hGroup)

Return the full name of the group.

The returned pointer is valid until hGroup is released.

This is the same as the C++ method GDALGroup::GetFullName().

char **GDALGroupGetMDArrayNames(GDALGroupH hGroup, CSLConstList papszOptions)

Return the list of multidimensional array names contained in this group.

This is the same as the C++ method GDALGroup::GetGroupNames().

返回

the array names, to be freed with CSLDestroy()

GDALMDArrayH GDALGroupOpenMDArray(GDALGroupH hGroup, const char *pszMDArrayName, CSLConstList papszOptions)

Open and return a multidimensional array.

This is the same as the C++ method GDALGroup::OpenMDArray().

返回

the array, to be freed with GDALMDArrayRelease(), or nullptr.

GDALMDArrayH GDALGroupOpenMDArrayFromFullname(GDALGroupH hGroup, const char *pszMDArrayName, CSLConstList papszOptions)

Open and return a multidimensional array from its fully qualified name.

This is the same as the C++ method GDALGroup::OpenMDArrayFromFullname().

Since

GDAL 3.2

返回

the array, to be freed with GDALMDArrayRelease(), or nullptr.

GDALMDArrayH GDALGroupResolveMDArray(GDALGroupH hGroup, const char *pszName, const char *pszStartingPoint, CSLConstList papszOptions)

Locate an array in a group and its subgroups by name.

See GDALGroup::ResolveMDArray() for description of the behavior.

Since

GDAL 3.2

char **GDALGroupGetGroupNames(GDALGroupH hGroup, CSLConstList papszOptions)

Return the list of sub-groups contained in this group.

This is the same as the C++ method GDALGroup::GetGroupNames().

返回

the group names, to be freed with CSLDestroy()

GDALGroupH GDALGroupOpenGroup(GDALGroupH hGroup, const char *pszSubGroupName, CSLConstList papszOptions)

Open and return a sub-group.

This is the same as the C++ method GDALGroup::OpenGroup().

返回

the sub-group, to be freed with GDALGroupRelease(), or nullptr.

GDALGroupH GDALGroupOpenGroupFromFullname(GDALGroupH hGroup, const char *pszMDArrayName, CSLConstList papszOptions)

Open and return a sub-group from its fully qualified name.

This is the same as the C++ method GDALGroup::OpenGroupFromFullname().

Since

GDAL 3.2

返回

the sub-group, to be freed with GDALGroupRelease(), or nullptr.

char **GDALGroupGetVectorLayerNames(GDALGroupH hGroup, CSLConstList papszOptions)

Return the list of layer names contained in this group.

This is the same as the C++ method GDALGroup::GetVectorLayerNames().

Since

3.4

返回

the group names, to be freed with CSLDestroy()

OGRLayerH GDALGroupOpenVectorLayer(GDALGroupH hGroup, const char *pszVectorLayerName, CSLConstList papszOptions)

Open and return a vector layer.

This is the same as the C++ method GDALGroup::OpenVectorLayer().

Note that the vector layer is owned by its parent GDALDatasetH, and thus the returned handled if only valid while the parent GDALDatasetH is kept opened.

Since

3.4

返回

the vector layer, or nullptr.

GDALDimensionH *GDALGroupGetDimensions(GDALGroupH hGroup, size_t *pnCount, CSLConstList papszOptions)

Return the list of dimensions contained in this group and used by its arrays.

The returned array must be freed with GDALReleaseDimensions(). If only the array itself needs to be freed, CPLFree() should be called (and GDALDimensionRelease() on individual array members).

This is the same as the C++ method GDALGroup::GetDimensions().

参数

• hGroup -- Group.

• pnCount -- Pointer to the number of values returned. Must NOT be NULL.

• papszOptions -- Driver specific options determining how dimensions should be retrieved. Pass nullptr for default behavior.

返回

an array of *pnCount dimensions.

GDALAttributeH GDALGroupGetAttribute(GDALGroupH hGroup, const char *pszName)

Return an attribute by its name.

This is the same as the C++ method GDALIHasAttribute::GetAttribute()

The returned attribute must be freed with GDALAttributeRelease().

GDALAttributeH *GDALGroupGetAttributes(GDALGroupH hGroup, size_t *pnCount, CSLConstList papszOptions)

Return the list of attributes contained in this group.

The returned array must be freed with GDALReleaseAttributes(). If only the array itself needs to be freed, CPLFree() should be called (and GDALAttributeRelease() on individual array members).

This is the same as the C++ method GDALGroup::GetAttributes().

参数

• hGroup -- Group.

• pnCount -- Pointer to the number of values returned. Must NOT be NULL.

• papszOptions -- Driver specific options determining how attributes should be retrieved. Pass nullptr for default behavior.

返回

an array of *pnCount attributes.

CSLConstList GDALGroupGetStructuralInfo(GDALGroupH hGroup)

Return structural information on the group.

This may be the compression, etc..

The return value should not be freed and is valid until GDALGroup is released or this function called again.

This is the same as the C++ method GDALGroup::GetStructuralInfo().

GDALGroupH GDALGroupCreateGroup(GDALGroupH hGroup, const char *pszSubGroupName, CSLConstList papszOptions)

Create a sub-group within a group.

This is the same as the C++ method GDALGroup::CreateGroup().

返回

the sub-group, to be freed with GDALGroupRelease(), or nullptr.

GDALDimensionH GDALGroupCreateDimension(GDALGroupH hGroup, const char *pszName, const char *pszType, const char *pszDirection, GUInt64 nSize, CSLConstList papszOptions)

Create a dimension within a group.

This is the same as the C++ method GDALGroup::CreateDimension().

返回

the dimension, to be freed with GDALDimensionRelease(), or nullptr.

GDALMDArrayH GDALGroupCreateMDArray(GDALGroupH hGroup, const char *pszName, size_t nDimensions, GDALDimensionH *pahDimensions, GDALExtendedDataTypeH hEDT, CSLConstList papszOptions)

Create a multidimensional array within a group.

This is the same as the C++ method GDALGroup::CreateMDArray().

返回

the array, to be freed with GDALMDArrayRelease(), or nullptr.

GDALAttributeH GDALGroupCreateAttribute(GDALGroupH hGroup, const char *pszName, size_t nDimensions, const GUInt64 *panDimensions, GDALExtendedDataTypeH hEDT, CSLConstList papszOptions)

Create a attribute within a group.

This is the same as the C++ method GDALGroup::CreateAttribute().

返回

the attribute, to be freed with GDALAttributeRelease(), or nullptr.

void GDALMDArrayRelease(GDALMDArrayH hMDArray)

Release the GDAL in-memory object associated with a GDALMDArray.

Note: when applied on a object coming from a driver, this does not destroy the object in the file, database, etc...

const char *GDALMDArrayGetName(GDALMDArrayH hArray)

Return array name.

This is the same as the C++ method GDALMDArray::GetName()

const char *GDALMDArrayGetFullName(GDALMDArrayH hArray)

Return array full name.

This is the same as the C++ method GDALMDArray::GetFullName()

GUInt64 GDALMDArrayGetTotalElementsCount(GDALMDArrayH hArray)

Return the total number of values in the array.

This is the same as the C++ method GDALAbstractMDArray::GetTotalElementsCount()

size_t GDALMDArrayGetDimensionCount(GDALMDArrayH hArray)

Return the number of dimensions.

This is the same as the C++ method GDALAbstractMDArray::GetDimensionCount()

GDALDimensionH *GDALMDArrayGetDimensions(GDALMDArrayH hArray, size_t *pnCount)

Return the dimensions of the array.

The returned array must be freed with GDALReleaseDimensions(). If only the array itself needs to be freed, CPLFree() should be called (and GDALDimensionRelease() on individual array members).

This is the same as the C++ method GDALAbstractMDArray::GetDimensions()

参数

• hArray -- Array.

• pnCount -- Pointer to the number of values returned. Must NOT be NULL.

返回

an array of *pnCount dimensions.

GDALExtendedDataTypeH GDALMDArrayGetDataType(GDALMDArrayH hArray)

Return the data type.

The return must be freed with GDALExtendedDataTypeRelease().

int GDALMDArrayRead(GDALMDArrayH hArray, const GUInt64 *arrayStartIdx, const size_t *count, const GInt64 *arrayStep, const GPtrDiff_t *bufferStride, GDALExtendedDataTypeH bufferDatatype, void *pDstBuffer, const void *pDstBufferAllocStart, size_t nDstBufferllocSize)

Read part or totality of a multidimensional array.

This is the same as the C++ method GDALAbstractMDArray::Read()

返回

TRUE in case of success.

int GDALMDArrayWrite(GDALMDArrayH hArray, const GUInt64 *arrayStartIdx, const size_t *count, const GInt64 *arrayStep, const GPtrDiff_t *bufferStride, GDALExtendedDataTypeH bufferDatatype, const void *pSrcBuffer, const void *psrcBufferAllocStart, size_t nSrcBufferllocSize)

Write part or totality of a multidimensional array.

This is the same as the C++ method GDALAbstractMDArray::Write()

返回

TRUE in case of success.

int GDALMDArrayAdviseRead(GDALMDArrayH hArray, const GUInt64 *arrayStartIdx, const size_t *count)

Advise driver of upcoming read requests.

This is the same as the C++ method GDALMDArray::AdviseRead()

Since

GDAL 3.2

返回

TRUE in case of success.

int GDALMDArrayAdviseReadEx(GDALMDArrayH hArray, const GUInt64 *arrayStartIdx, const size_t *count, CSLConstList papszOptions)

Advise driver of upcoming read requests.

This is the same as the C++ method GDALMDArray::AdviseRead()

Since

GDAL 3.4

返回

TRUE in case of success.

GDALAttributeH GDALMDArrayGetAttribute(GDALMDArrayH hArray, const char *pszName)

Return an attribute by its name.

This is the same as the C++ method GDALIHasAttribute::GetAttribute()

The returned attribute must be freed with GDALAttributeRelease().

GDALAttributeH *GDALMDArrayGetAttributes(GDALMDArrayH hArray, size_t *pnCount, CSLConstList papszOptions)

Return the list of attributes contained in this array.

The returned array must be freed with GDALReleaseAttributes(). If only the array itself needs to be freed, CPLFree() should be called (and GDALAttributeRelease() on individual array members).

This is the same as the C++ method GDALMDArray::GetAttributes().

参数

• hArray -- Array.

• pnCount -- Pointer to the number of values returned. Must NOT be NULL.

• papszOptions -- Driver specific options determining how attributes should be retrieved. Pass nullptr for default behavior.

返回

an array of *pnCount attributes.

GDALAttributeH GDALMDArrayCreateAttribute(GDALMDArrayH hArray, const char *pszName, size_t nDimensions, const GUInt64 *panDimensions, GDALExtendedDataTypeH hEDT, CSLConstList papszOptions)

Create a attribute within an array.

This is the same as the C++ method GDALMDArray::CreateAttribute().

返回

the attribute, to be freed with GDALAttributeRelease(), or nullptr.

const void *GDALMDArrayGetRawNoDataValue(GDALMDArrayH hArray)

Return the nodata value as a "raw" value.

The value returned might be nullptr in case of no nodata value. When a nodata value is registered, a non-nullptr will be returned whose size in bytes is GetDataType().GetSize().

The returned value should not be modified or freed.

This is the same as the ++ method GDALMDArray::GetRawNoDataValue().

返回

nullptr or a pointer to GetDataType().GetSize() bytes.

double GDALMDArrayGetNoDataValueAsDouble(GDALMDArrayH hArray, int *pbHasNoDataValue)

Return the nodata value as a double.

The value returned might be nullptr in case of no nodata value. When a nodata value is registered, a non-nullptr will be returned whose size in bytes is GetDataType().GetSize().

This is the same as the C++ method GDALMDArray::GetNoDataValueAsDouble().

参数

• hArray -- Array handle.

• pbHasNoDataValue -- Pointer to a output boolean that will be set to true if a nodata value exists and can be converted to double. Might be nullptr.

返回

the nodata value as a double. A 0.0 value might also indicate the absence of a nodata value or an error in the conversion (*pbHasNoDataValue will be set to false then).

int64_t GDALMDArrayGetNoDataValueAsInt64(GDALMDArrayH hArray, int *pbHasNoDataValue)

Return the nodata value as a Int64.

This is the same as the C++ method GDALMDArray::GetNoDataValueAsInt64().

Since

GDAL 3.5

参数

• hArray -- Array handle.

• pbHasNoDataValue -- Pointer to a output boolean that will be set to true if a nodata value exists and can be converted to Int64. Might be nullptr.

返回

the nodata value as a Int64.

uint64_t GDALMDArrayGetNoDataValueAsUInt64(GDALMDArrayH hArray, int *pbHasNoDataValue)

Return the nodata value as a UInt64.

This is the same as the C++ method GDALMDArray::GetNoDataValueAsInt64().

Since

GDAL 3.5

参数

• hArray -- Array handle.

• pbHasNoDataValue -- Pointer to a output boolean that will be set to true if a nodata value exists and can be converted to UInt64. Might be nullptr.

返回

the nodata value as a UInt64.

int GDALMDArraySetRawNoDataValue(GDALMDArrayH hArray, const void*)

Set the nodata value as a "raw" value.

This is the same as the C++ method GDALMDArray::SetRawNoDataValue(const void*).

返回

TRUE in case of success.

int GDALMDArraySetNoDataValueAsDouble(GDALMDArrayH hArray, double dfNoDataValue)

Set the nodata value as a double.

If the natural data type of the attribute/array is not double, type conversion will occur to the type returned by GetDataType().

This is the same as the C++ method GDALMDArray::SetNoDataValue(double).

返回

TRUE in case of success.

int GDALMDArraySetNoDataValueAsInt64(GDALMDArrayH hArray, int64_t nNoDataValue)

Set the nodata value as a Int64.

If the natural data type of the attribute/array is not Int64, type conversion will occur to the type returned by GetDataType().

This is the same as the C++ method GDALMDArray::SetNoDataValue(int64_t).

Since

GDAL 3.5

返回

TRUE in case of success.

int GDALMDArraySetNoDataValueAsUInt64(GDALMDArrayH hArray, uint64_t nNoDataValue)

Set the nodata value as a UInt64.

If the natural data type of the attribute/array is not UInt64, type conversion will occur to the type returned by GetDataType().

This is the same as the C++ method GDALMDArray::SetNoDataValue(uint64_t).

Since

GDAL 3.5

返回

TRUE in case of success.

int GDALMDArraySetScale(GDALMDArrayH hArray, double dfScale)

Set the scale value to apply to raw values.

unscaled_value = raw_value * GetScale() + GetOffset()

This is the same as the C++ method GDALMDArray::SetScale().

返回

TRUE in case of success.

int GDALMDArraySetScaleEx(GDALMDArrayH hArray, double dfScale, GDALDataType eStorageType)

Set the scale value to apply to raw values.

unscaled_value = raw_value * GetScale() + GetOffset()

This is the same as the C++ method GDALMDArray::SetScale().

Since

GDAL 3.3

返回

TRUE in case of success.

double GDALMDArrayGetScale(GDALMDArrayH hArray, int *pbHasValue)

Get the scale value to apply to raw values.

unscaled_value = raw_value * GetScale() + GetOffset()

This is the same as the C++ method GDALMDArray::GetScale().

返回

the scale value

double GDALMDArrayGetScaleEx(GDALMDArrayH hArray, int *pbHasValue, GDALDataType *peStorageType)

Get the scale value to apply to raw values.

unscaled_value = raw_value * GetScale() + GetScale()

This is the same as the C++ method GDALMDArray::GetScale().

Since

GDAL 3.3

返回

the scale value

int GDALMDArraySetOffset(GDALMDArrayH hArray, double dfOffset)

Set the scale value to apply to raw values.

unscaled_value = raw_value * GetScale() + GetOffset()

This is the same as the C++ method GDALMDArray::SetOffset().

返回

TRUE in case of success.

int GDALMDArraySetOffsetEx(GDALMDArrayH hArray, double dfOffset, GDALDataType eStorageType)

Set the scale value to apply to raw values.

unscaled_value = raw_value * GetOffset() + GetOffset()

This is the same as the C++ method GDALMDArray::SetOffset().

Since

GDAL 3.3

返回

TRUE in case of success.

double GDALMDArrayGetOffset(GDALMDArrayH hArray, int *pbHasValue)

Get the scale value to apply to raw values.

unscaled_value = raw_value * GetScale() + GetOffset()

This is the same as the C++ method GDALMDArray::GetOffset().

返回

the scale value

double GDALMDArrayGetOffsetEx(GDALMDArrayH hArray, int *pbHasValue, GDALDataType *peStorageType)

Get the scale value to apply to raw values.

unscaled_value = raw_value * GetScale() + GetOffset()

This is the same as the C++ method GDALMDArray::GetOffset().

Since

GDAL 3.3

返回

the scale value

GUInt64 *GDALMDArrayGetBlockSize(GDALMDArrayH hArray, size_t *pnCount)

Return the "natural" block size of the array along all dimensions.

Some drivers might organize the array in tiles/blocks and reading/writing aligned on those tile/block boundaries will be more efficient.

The returned number of elements in the vector is the same as GetDimensionCount(). A value of 0 should be interpreted as no hint regarding the natural block size along the considered dimension. "Flat" arrays will typically return a vector of values set to 0.

The default implementation will return a vector of values set to 0.

This method is used by GetProcessingChunkSize().

Pedantic note: the returned type is GUInt64, so in the highly unlikeley theoretical case of a 32-bit platform, this might exceed its size_t allocation capabilities.

This is the same as the C++ method GDALAbstractMDArray::GetBlockSize().

返回

the block size, in number of elements along each dimension.

int GDALMDArraySetUnit(GDALMDArrayH hArray, const char*)

Set the variable unit.

Values should conform as much as possible with those allowed by the NetCDF CF conventions: http://cfconventions.org/Data/cf-conventions/cf-conventions-1.7/cf-conventions.html#units but others might be returned.

Few examples are "meter", "degrees", "second", ... Empty value means unknown.

This is the same as the C function GDALMDArraySetUnit()

参数

• hArray -- array.

• pszUnit -- unit name.

返回

TRUE in case of success.

const char *GDALMDArrayGetUnit(GDALMDArrayH hArray)

Return the array unit.

Values should conform as much as possible with those allowed by the NetCDF CF conventions: http://cfconventions.org/Data/cf-conventions/cf-conventions-1.7/cf-conventions.html#units but others might be returned.

Few examples are "meter", "degrees", "second", ... Empty value means unknown.

The return value should not be freed and is valid until GDALMDArray is released or this function called again.

This is the same as the C++ method GDALMDArray::GetUnit().

int GDALMDArraySetSpatialRef(GDALMDArrayH, OGRSpatialReferenceH)

Assign a spatial reference system object to the the array.

This is the same as the C++ method GDALMDArray::SetSpatialRef().

返回

TRUE in case of success.

OGRSpatialReferenceH GDALMDArrayGetSpatialRef(GDALMDArrayH hArray)

Return the spatial reference system object associated with the array.

This is the same as the C++ method GDALMDArray::GetSpatialRef().

The returned object must be freed with OSRDestroySpatialReference().

size_t *GDALMDArrayGetProcessingChunkSize(GDALMDArrayH hArray, size_t *pnCount, size_t nMaxChunkMemory)

Return an optimal chunk size for read/write operations, given the natural block size and memory constraints specified.

This method will use GetBlockSize() to define a chunk whose dimensions are multiple of those returned by GetBlockSize() (unless the block define by GetBlockSize() is larger than nMaxChunkMemory, in which case it will be returned by this method).

This is the same as the C++ method GDALAbstractMDArray::GetProcessingChunkSize().

参数

• hArray -- Array.

• pnCount -- Pointer to the number of values returned. Must NOT be NULL.

• nMaxChunkMemory -- Maximum amount of memory, in bytes, to use for the chunk.

返回

the chunk size, in number of elements along each dimension.

CSLConstList GDALMDArrayGetStructuralInfo(GDALMDArrayH hArray)

Return structural information on the array.

This may be the compression, etc..

The return value should not be freed and is valid until GDALMDArray is released or this function called again.

This is the same as the C++ method GDALMDArray::GetStructuralInfo().

GDALMDArrayH GDALMDArrayGetView(GDALMDArrayH hArray, const char *pszViewExpr)

Return a view of the array using slicing or field access.

The returned object should be released with GDALMDArrayRelease().

This is the same as the C++ method GDALMDArray::GetView().

GDALMDArrayH GDALMDArrayTranspose(GDALMDArrayH hArray, size_t nNewAxisCount, const int *panMapNewAxisToOldAxis)

Return a view of the array whose axis have been reordered.

The returned object should be released with GDALMDArrayRelease().

This is the same as the C++ method GDALMDArray::Transpose().

GDALMDArrayH GDALMDArrayGetUnscaled(GDALMDArrayH hArray)

Return an array that is the unscaled version of the current one.

That is each value of the unscaled array will be unscaled_value = raw_value * GetScale() + GetOffset()

Starting with GDAL 3.3, the Write() method is implemented and will convert from unscaled values to raw values.

The returned object should be released with GDALMDArrayRelease().

This is the same as the C++ method GDALMDArray::GetUnscaled().

GDALMDArrayH GDALMDArrayGetMask(GDALMDArrayH hArray, CSLConstList papszOptions)

Return an array that is a mask for the current array.

This array will be of type Byte, with values set to 0 to indicate invalid pixels of the current array, and values set to 1 to indicate valid pixels.

The returned object should be released with GDALMDArrayRelease().

This is the same as the C++ method GDALMDArray::GetMask().

GDALDatasetH GDALMDArrayAsClassicDataset(GDALMDArrayH hArray, size_t iXDim, size_t iYDim)

Return a view of this array as a "classic" GDALDataset (ie 2D)

Only 2D or more arrays are supported.

In the case of > 2D arrays, additional dimensions will be represented as raster bands.

The "reverse" method is GDALRasterBand::AsMDArray().

This is the same as the C++ method GDALMDArray::AsClassicDataset().

参数

• hArray -- Array.

• iXDim -- Index of the dimension that will be used as the X/width axis.

• iYDim -- Index of the dimension that will be used as the Y/height axis.

返回

a new GDALDataset that must be freed with GDALClose(), or nullptr

CPLErr GDALMDArrayGetStatistics(GDALMDArrayH hArray, GDALDatasetH, int bApproxOK, int bForce, double *pdfMin, double *pdfMax, double *pdfMean, double *pdfStdDev, GUInt64 *pnValidCount, GDALProgressFunc pfnProgress, void *pProgressData)

Fetch statistics.

This is the same as the C++ method GDALMDArray::GetStatistics().

Since

GDAL 3.2

int GDALMDArrayComputeStatistics(GDALMDArrayH hArray, GDALDatasetH, int bApproxOK, double *pdfMin, double *pdfMax, double *pdfMean, double *pdfStdDev, GUInt64 *pnValidCount, GDALProgressFunc, void *pProgressData)

Compute statistics.

This is the same as the C++ method GDALMDArray::ComputeStatistics().

Since

GDAL 3.2

GDALMDArrayH GDALMDArrayGetResampled(GDALMDArrayH hArray, size_t nNewDimCount, const GDALDimensionH *pahNewDims, GDALRIOResampleAlg resampleAlg, OGRSpatialReferenceH hTargetSRS, CSLConstList papszOptions)

Return an array that is a resampled / reprojected view of the current array.

This is the same as the C++ method GDALMDArray::GetResampled().

Currently this method can only resample along the last 2 dimensions.

The returned object should be released with GDALMDArrayRelease().

Since

3.4

GDALMDArrayH *GDALMDArrayGetCoordinateVariables(GDALMDArrayH hArray, size_t *pnCount)

Return coordinate variables.

The returned array must be freed with GDALReleaseArrays(). If only the array itself needs to be freed, CPLFree() should be called (and GDALMDArrayRelease() on individual array members).

This is the same as the C++ method GDALMDArray::GetCoordinateVariables()

Since

3.4

参数

• hArray -- Array.

• pnCount -- Pointer to the number of values returned. Must NOT be NULL.

返回

an array of *pnCount arrays.

void GDALReleaseArrays(GDALMDArrayH *arrays, size_t nCount)

Free the return of GDALMDArrayGetCoordinateVariables()

参数

• arrays -- return pointer of above methods

• nCount -- *pnCount value returned by above methods

int GDALMDArrayCache(GDALMDArrayH hArray, CSLConstList papszOptions)

Cache the content of the array into an auxiliary filename.

This is the same as the C++ method GDALMDArray::Cache().

Since

GDAL 3.4

void GDALAttributeRelease(GDALAttributeH hAttr)

Release the GDAL in-memory object associated with a GDALAttribute.

Note: when applied on a object coming from a driver, this does not destroy the object in the file, database, etc...

void GDALReleaseAttributes(GDALAttributeH *attributes, size_t nCount)

Free the return of GDALGroupGetAttributes() or GDALMDArrayGetAttributes()

参数

• attributes -- return pointer of above methods

• nCount -- *pnCount value returned by above methods

const char *GDALAttributeGetName(GDALAttributeH hAttr)

Return the name of the attribute.

The returned pointer is valid until hAttr is released.

This is the same as the C++ method GDALAttribute::GetName().

const char *GDALAttributeGetFullName(GDALAttributeH hAttr)

Return the full name of the attribute.

The returned pointer is valid until hAttr is released.

This is the same as the C++ method GDALAttribute::GetFullName().

GUInt64 GDALAttributeGetTotalElementsCount(GDALAttributeH hAttr)

Return the total number of values in the attribute.

This is the same as the C++ method GDALAbstractMDArray::GetTotalElementsCount()

size_t GDALAttributeGetDimensionCount(GDALAttributeH hAttr)

Return the number of dimensions.

This is the same as the C++ method GDALAbstractMDArray::GetDimensionCount()

GUInt64 *GDALAttributeGetDimensionsSize(GDALAttributeH hAttr, size_t *pnCount)

Return the dimension sizes of the attribute.

The returned array must be freed with CPLFree()

参数

• hAttr -- Attribute.

• pnCount -- Pointer to the number of values returned. Must NOT be NULL.

返回

an array of *pnCount values.

GDALExtendedDataTypeH GDALAttributeGetDataType(GDALAttributeH hAttr)

Return the data type.

The return must be freed with GDALExtendedDataTypeRelease().

GByte *GDALAttributeReadAsRaw(GDALAttributeH hAttr, size_t *pnSize)

Return the raw value of an attribute.

This is the same as the C++ method GDALAttribute::ReadAsRaw().

The returned buffer must be freed with GDALAttributeFreeRawResult()

参数

• hAttr -- Attribute.

• pnSize -- Pointer to the number of bytes returned. Must NOT be NULL.

返回

a buffer of *pnSize bytes.

void GDALAttributeFreeRawResult(GDALAttributeH hAttr, GByte *raw, size_t nSize)

Free the return of GDALAttributeAsRaw()

const char *GDALAttributeReadAsString(GDALAttributeH hAttr)

Return the value of an attribute as a string.

The returned string should not be freed, and its lifetime does not excess a next call to ReadAsString() on the same object, or the deletion of the object itself.

This function will only return the first element if there are several.

This is the same as the C++ method GDALAttribute::ReadAsString()

返回

a string, or nullptr.

int GDALAttributeReadAsInt(GDALAttributeH hAttr)

Return the value of an attribute as a integer.

This function will only return the first element if there are several.

It can fail if its value can be converted to integer.

This is the same as the C++ method GDALAttribute::ReadAsInt()

返回

a integer, or INT_MIN in case of error.

double GDALAttributeReadAsDouble(GDALAttributeH hAttr)

Return the value of an attribute as a double.

This function will only return the first element if there are several.

It can fail if its value can be converted to double.

This is the same as the C++ method GDALAttribute::ReadAsDoubl()

返回

a double value.

char **GDALAttributeReadAsStringArray(GDALAttributeH hAttr)

Return the value of an attribute as an array of strings.

This is the same as the C++ method GDALAttribute::ReadAsStringArray()

The return value must be freed with CSLDestroy().

int *GDALAttributeReadAsIntArray(GDALAttributeH hAttr, size_t *pnCount)

Return the value of an attribute as an array of integers.

This is the same as the C++ method GDALAttribute::ReadAsIntArray()

参数

• hAttr -- Attribute

• pnCount -- Pointer to the number of values returned. Must NOT be NULL.

返回

array to be freed with CPLFree(), or nullptr.

double *GDALAttributeReadAsDoubleArray(GDALAttributeH hAttr, size_t *pnCount)

Return the value of an attribute as an array of doubles.

This is the same as the C++ method GDALAttribute::ReadAsDoubleArray()

参数

• hAttr -- Attribute

• pnCount -- Pointer to the number of values returned. Must NOT be NULL.

返回

array to be freed with CPLFree(), or nullptr.

int GDALAttributeWriteRaw(GDALAttributeH hAttr, const void*, size_t)

Write an attribute from raw values expressed in GetDataType()

The values should be provided in the type of GetDataType() and there should be exactly GetTotalElementsCount() of them. If GetDataType() is a string, each value should be a char* pointer.

This is the same as the C++ method GDALAttribute::Write(const void*, size_t).

参数

• hAttr -- Attribute

• pabyValue -- Buffer of nLen bytes.

• nLength -- Size of pabyValue in bytes. Should be equal to GetTotalElementsCount() * GetDataType().GetSize()

返回

TRUE in case of success.

int GDALAttributeWriteString(GDALAttributeH hAttr, const char*)

Write an attribute from a string value.

Type conversion will be performed if needed. If the attribute contains multiple values, only the first one will be updated.

This is the same as the C++ method GDALAttribute::Write(const char*)

参数

• hAttr -- Attribute

• pszVal -- Pointer to a string.

返回

TRUE in case of success.

int GDALAttributeWriteStringArray(GDALAttributeH hAttr, CSLConstList)

Write an attribute from an array of strings.

Type conversion will be performed if needed.

Exactly GetTotalElementsCount() strings must be provided

This is the same as the C++ method GDALAttribute::Write(CSLConstList)

参数

• hAttr -- Attribute

• papszValues -- Array of strings.

返回

TRUE in case of success.

int GDALAttributeWriteInt(GDALAttributeH hAttr, int)

Write an attribute from a integer value.

Type conversion will be performed if needed. If the attribute contains multiple values, only the first one will be updated.

This is the same as the C++ method GDALAttribute::WriteInt()

参数

• hAttr -- Attribute

• nVal -- Value.

返回

TRUE in case of success.

int GDALAttributeWriteDouble(GDALAttributeH hAttr, double)

Write an attribute from a double value.

Type conversion will be performed if needed. If the attribute contains multiple values, only the first one will be updated.

This is the same as the C++ method GDALAttribute::Write(double);

参数

• hAttr -- Attribute

• dfVal -- Value.

返回

TRUE in case of success.

int GDALAttributeWriteDoubleArray(GDALAttributeH hAttr, const double*, size_t)

Write an attribute from an array of double.

Type conversion will be performed if needed.

Exactly GetTotalElementsCount() strings must be provided

This is the same as the C++ method GDALAttribute::Write(const double *, size_t)

参数

• hAttr -- Attribute

• padfValues -- Array of double.

• nCount -- Should be equal to GetTotalElementsCount().

返回

TRUE in case of success.

void GDALDimensionRelease(GDALDimensionH hDim)

Release the GDAL in-memory object associated with a GDALDimension.

Note: when applied on a object coming from a driver, this does not destroy the object in the file, database, etc...

void GDALReleaseDimensions(GDALDimensionH *dims, size_t nCount)

Free the return of GDALGroupGetDimensions() or GDALMDArrayGetDimensions()

参数

• dims -- return pointer of above methods

• nCount -- *pnCount value returned by above methods

const char *GDALDimensionGetName(GDALDimensionH hDim)

Return dimension name.

This is the same as the C++ method GDALDimension::GetName()

const char *GDALDimensionGetFullName(GDALDimensionH hDim)

Return dimension full name.

This is the same as the C++ method GDALDimension::GetFullName()

const char *GDALDimensionGetType(GDALDimensionH hDim)

Return dimension type.

This is the same as the C++ method GDALDimension::GetType()

const char *GDALDimensionGetDirection(GDALDimensionH hDim)

Return dimension direction.

This is the same as the C++ method GDALDimension::GetDirection()

GUInt64 GDALDimensionGetSize(GDALDimensionH hDim)

Return the size, that is the number of values along the dimension.

This is the same as the C++ method GDALDimension::GetSize()

GDALMDArrayH GDALDimensionGetIndexingVariable(GDALDimensionH hDim)

Return the variable that is used to index the dimension (if there is one).

This is the array, typically one-dimensional, describing the values taken by the dimension.

The returned value should be freed with GDALMDArrayRelease().

This is the same as the C++ method GDALDimension::GetIndexingVariable()

int GDALDimensionSetIndexingVariable(GDALDimensionH hDim, GDALMDArrayH hArray)

Set the variable that is used to index the dimension.

This is the array, typically one-dimensional, describing the values taken by the dimension.

This is the same as the C++ method GDALDimension::SetIndexingVariable()

返回

TRUE in case of success.

struct GDALRasterIOExtraArg

#include <gdal.h>

Structure to pass extra arguments to RasterIO() method, must be initialized with INIT_RASTERIO_EXTRA_ARG.

Since

GDAL 2.0

公共成员

int nVersion

Version of structure (to allow future extensions of the structure)

GDALRIOResampleAlg eResampleAlg

Resampling algorithm

GDALProgressFunc pfnProgress

Progress callback

void *pProgressData

Progress callback user data

int bFloatingPointWindowValidity

Indicate if dfXOff, dfYOff, dfXSize and dfYSize are set. Mostly reserved from the VRT driver to communicate a more precise source window. Must be such that dfXOff - nXOff < 1.0 and dfYOff - nYOff < 1.0 and nXSize - dfXSize < 1.0 and nYSize - dfYSize < 1.0

double dfXOff

Pixel offset to the top left corner. Only valid if bFloatingPointWindowValidity = TRUE

double dfYOff

Line offset to the top left corner. Only valid if bFloatingPointWindowValidity = TRUE

double dfXSize

Width in pixels of the area of interest. Only valid if bFloatingPointWindowValidity = TRUE

double dfYSize

Height in pixels of the area of interest. Only valid if bFloatingPointWindowValidity = TRUE

struct GDAL_GCP

#include <gdal.h>

Ground Control Point.

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char *pszId

Unique identifier, often numeric.

char *pszInfo

Informational message or "".

double dfGCPPixel

Pixel (x) location of GCP on raster.

double dfGCPLine

Line (y) location of GCP on raster.

double dfGCPX

X position of GCP in georeferenced space.

double dfGCPY

Y position of GCP in georeferenced space.

double dfGCPZ

Elevation of GCP, or zero if not known.

struct GDALRPCInfoV2

#include <gdal.h>

Structure to store Rational Polynomial Coefficients / Rigorous Projection Model.

See http://geotiff.maptools.org/rpc_prop.html

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double dfLINE_OFF

Line offset

double dfSAMP_OFF

Sample/Pixel offset

double dfLAT_OFF

Latitude offset

double dfLONG_OFF

Longitude offset

double dfHEIGHT_OFF

Height offset

double dfLINE_SCALE

Line scale

double dfSAMP_SCALE

Sample/Pixel scale

double dfLAT_SCALE

Latitude scale

double dfLONG_SCALE

Longitude scale

double dfHEIGHT_SCALE

Height scale

double adfLINE_NUM_COEFF[20]

Line Numerator Coefficients

double adfLINE_DEN_COEFF[20]

Line Denominator Coefficients

double adfSAMP_NUM_COEFF[20]

Sample/Pixel Numerator Coefficients

double adfSAMP_DEN_COEFF[20]

Sample/Pixel Denominator Coefficients

double dfMIN_LONG

Minimum longitude

double dfMIN_LAT

Minimum latitude

double dfMAX_LONG

Maximum longitude

double dfMAX_LAT

Maximum latitude

double dfERR_BIAS

Bias error

double dfERR_RAND

Random error

struct GDALColorEntry

#include <gdal.h>

Color tuple.

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short c1

gray, red, cyan or hue

short c2

green, magenta, or lightness

short c3

blue, yellow, or saturation

short c4

alpha or blackband