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GDALPamRasterBand Class Referenceabstract

PAM raster band. More...

#include <gdal_pam.h>

Inheritance diagram for GDALPamRasterBand:
GDALRasterBand GDALMajorObject

Public Member Functions

void SetDescription (const char *) override
 Set object description. More...
 
CPLErr SetNoDataValue (double) override
 Set the no data value for this band. More...
 
CPLErr SetNoDataValueAsInt64 (int64_t nNoData) override
 Set the no data value for this band. More...
 
CPLErr SetNoDataValueAsUInt64 (uint64_t nNoData) override
 Set the no data value for this band. More...
 
double GetNoDataValue (int *pbSuccess=nullptr) override
 Fetch the no data value for this band. More...
 
int64_t GetNoDataValueAsInt64 (int *pbSuccess=nullptr) override
 Fetch the no data value for this band. More...
 
uint64_t GetNoDataValueAsUInt64 (int *pbSuccess=nullptr) override
 Fetch the no data value for this band. More...
 
CPLErr DeleteNoDataValue () override
 Remove the no data value for this band. More...
 
CPLErr SetColorTable (GDALColorTable *) override
 Set the raster color table. More...
 
GDALColorTableGetColorTable () override
 Fetch the color table associated with band. More...
 
CPLErr SetColorInterpretation (GDALColorInterp) override
 Set color interpretation of a band. More...
 
GDALColorInterp GetColorInterpretation () override
 How should this band be interpreted as color? More...
 
const char * GetUnitType () override
 Return raster unit type. More...
 
CPLErr SetUnitType (const char *) override
 Set unit type. More...
 
char ** GetCategoryNames () override
 Fetch the list of category names for this raster. More...
 
CPLErr SetCategoryNames (char **) override
 Set the category names for this band. More...
 
double GetOffset (int *pbSuccess=nullptr) override
 Fetch the raster value offset. More...
 
CPLErr SetOffset (double) override
 Set scaling offset. More...
 
double GetScale (int *pbSuccess=nullptr) override
 Fetch the raster value scale. More...
 
CPLErr SetScale (double) override
 Set scaling ratio. More...
 
CPLErr GetHistogram (double dfMin, double dfMax, int nBuckets, GUIntBig *panHistogram, int bIncludeOutOfRange, int bApproxOK, GDALProgressFunc, void *pProgressData) override
 Compute raster histogram. More...
 
CPLErr GetDefaultHistogram (double *pdfMin, double *pdfMax, int *pnBuckets, GUIntBig **ppanHistogram, int bForce, GDALProgressFunc, void *pProgressData) override
 Fetch default raster histogram. More...
 
CPLErr SetDefaultHistogram (double dfMin, double dfMax, int nBuckets, GUIntBig *panHistogram) override
 Set default histogram. More...
 
CPLErr SetMetadata (char **papszMetadata, const char *pszDomain="") override
 Set metadata. More...
 
CPLErr SetMetadataItem (const char *pszName, const char *pszValue, const char *pszDomain="") override
 Set single metadata item. More...
 
GDALRasterAttributeTableGetDefaultRAT () override
 Fetch default Raster Attribute Table. More...
 
CPLErr SetDefaultRAT (const GDALRasterAttributeTable *) override
 Set default Raster Attribute Table. More...
 
int GetXSize ()
 Fetch XSize of raster. More...
 
int GetYSize ()
 Fetch YSize of raster. More...
 
int GetBand ()
 Fetch the band number. More...
 
GDALDatasetGetDataset ()
 Fetch the owning dataset handle. More...
 
GDALDataType GetRasterDataType (void)
 Fetch the pixel data type for this band. More...
 
void GetBlockSize (int *, int *)
 Fetch the "natural" block size of this band. More...
 
CPLErr GetActualBlockSize (int, int, int *, int *)
 Fetch the actual block size for a given block offset. More...
 
virtual GDALSuggestedBlockAccessPattern GetSuggestedBlockAccessPattern () const
 Return the suggested/most efficient access pattern to blocks (for read operations). More...
 
GDALAccess GetAccess ()
 Find out if we have update permission for this band. More...
 
CPLErr RasterIO (GDALRWFlag, int, int, int, int, void *, int, int, GDALDataType, GSpacing, GSpacing, GDALRasterIOExtraArg *psExtraArg)
 Read/write a region of image data for this band. More...
 
CPLErr ReadBlock (int, int, void *)
 Read a block of image data efficiently. More...
 
CPLErr WriteBlock (int, int, void *)
 Write a block of image data efficiently. More...
 
GDALRasterBlockGetLockedBlockRef (int nXBlockOff, int nYBlockOff, int bJustInitialize=FALSE)
 Fetch a pointer to an internally cached raster block. More...
 
GDALRasterBlockTryGetLockedBlockRef (int nXBlockOff, int nYBlockYOff)
 Try fetching block ref. More...
 
CPLErr FlushBlock (int, int, int bWriteDirtyBlock=TRUE)
 Flush a block out of the block cache. More...
 
unsigned char * GetIndexColorTranslationTo (GDALRasterBand *poReferenceBand, unsigned char *pTranslationTable=nullptr, int *pApproximateMatching=nullptr)
 Compute translation table for color tables. More...
 
virtual CPLErr FlushCache (bool bAtClosing=false)
 Flush raster data cache. More...
 
virtual CPLErr DropCache ()
 Drop raster data cache : data in cache will be lost. More...
 
virtual double GetMinimum (int *pbSuccess=nullptr)
 Fetch the minimum value for this band. More...
 
virtual double GetMaximum (int *pbSuccess=nullptr)
 Fetch the maximum value for this band. More...
 
virtual CPLErr Fill (double dfRealValue, double dfImaginaryValue=0)
 Fill this band with a constant value. More...
 
virtual CPLErr GetStatistics (int bApproxOK, int bForce, double *pdfMin, double *pdfMax, double *pdfMean, double *padfStdDev)
 Fetch image statistics. More...
 
virtual CPLErr ComputeStatistics (int bApproxOK, double *pdfMin, double *pdfMax, double *pdfMean, double *pdfStdDev, GDALProgressFunc, void *pProgressData)
 Compute image statistics. More...
 
virtual CPLErr SetStatistics (double dfMin, double dfMax, double dfMean, double dfStdDev)
 Set statistics on band. More...
 
virtual CPLErr ComputeRasterMinMax (int, double *)
 Compute the min/max values for a band. More...
 
virtual const char * GetMetadataItem (const char *pszName, const char *pszDomain="") override
 Fetch single metadata item. More...
 
virtual int HasArbitraryOverviews ()
 Check for arbitrary overviews. More...
 
virtual int GetOverviewCount ()
 Return the number of overview layers available. More...
 
virtual GDALRasterBandGetOverview (int)
 Fetch overview raster band object. More...
 
virtual GDALRasterBandGetRasterSampleOverview (GUIntBig)
 Fetch best sampling overview. More...
 
virtual CPLErr BuildOverviews (const char *pszResampling, int nOverviews, const int *panOverviewList, GDALProgressFunc pfnProgress, void *pProgressData, CSLConstList papszOptions)
 If the operation is unsupported for the indicated dataset, then CE_Failure is returned, and CPLGetLastErrorNo() will return CPLE_NotSupported. More...
 
virtual CPLErr AdviseRead (int nXOff, int nYOff, int nXSize, int nYSize, int nBufXSize, int nBufYSize, GDALDataType eBufType, char **papszOptions)
 Advise driver of upcoming read requests. More...
 
virtual GDALRasterBandGetMaskBand ()
 Return the mask band associated with the band. More...
 
virtual int GetMaskFlags ()
 Return the status flags of the mask band associated with the band. More...
 
virtual CPLErr CreateMaskBand (int nFlagsIn)
 Adds a mask band to the current band. More...
 
virtual bool IsMaskBand () const
 Returns whether a band is a mask band. More...
 
virtual GDALMaskValueRange GetMaskValueRange () const
 Returns the range of values that a mask band can take. More...
 
virtual CPLVirtualMem * GetVirtualMemAuto (GDALRWFlag eRWFlag, int *pnPixelSpace, GIntBig *pnLineSpace, char **papszOptions)
 Create a CPLVirtualMem object from a GDAL raster band object. More...
 
int GetDataCoverageStatus (int nXOff, int nYOff, int nXSize, int nYSize, int nMaskFlagStop=0, double *pdfDataPct=nullptr)
 Get the coverage status of a sub-window of the raster. More...
 
std::shared_ptr< GDALMDArrayAsMDArray () const
 Return a view of this raster band as a 2D multidimensional GDALMDArray. More...
 
void ReportError (CPLErr eErrClass, CPLErrorNum err_no, const char *fmt,...) CPL_PRINT_FUNC_FORMAT(4
 Emits an error related to a raster band. More...
 
int GetMOFlags () const
 Returns the GMO_ flags. More...
 
void SetMOFlags (int nFlagsIn)
 Assign GMO_flags. More...
 
virtual const char * GetDescription () const
 Fetch object description. More...
 
virtual char ** GetMetadataDomainList ()
 Fetch list of metadata domains. More...
 
virtual char ** GetMetadata (const char *pszDomain="")
 Fetch metadata. More...
 

Static Public Member Functions

void static GDALRasterBandH ToHandle (GDALRasterBand *poBand)
 Convert a GDALRasterBand* to a GDALRasterBandH. More...
 
static GDALMajorObjectH ToHandle (GDALMajorObject *poMajorObject)
 Convert a GDALMajorObject* to a GDALMajorObjectH. More...
 
static GDALRasterBandFromHandle (GDALRasterBandH hBand)
 Convert a GDALRasterBandH to a GDALRasterBand*. More...
 

Protected Member Functions

virtual CPLErr IReadBlock (int nBlockXOff, int nBlockYOff, void *pData)=0
 Default internal implementation ... to be overridden by subclasses that support reading. More...
 
virtual CPLErr IWriteBlock (int nBlockXOff, int nBlockYOff, void *pData)
 Write a block of data. More...
 
virtual CPLErr IRasterIO (GDALRWFlag, int, int, int, int, void *, int, int, GDALDataType, GSpacing, GSpacing, GDALRasterIOExtraArg *psExtraArg)
 Read/write a region of image data for this band. More...
 
virtual int IGetDataCoverageStatus (int nXOff, int nYOff, int nXSize, int nYSize, int nMaskFlagStop, double *pdfDataPct)
 Get the coverage status of a sub-window of the raster. More...
 
char ** BuildMetadataDomainList (char **papszList, int bCheckNonEmpty,...) CPL_NULL_TERMINATED
 Helper function for custom implementations of GetMetadataDomainList() More...
 

Friends

class GDALPamDataset
 

Detailed Description

PAM raster band.

Member Function Documentation

◆ AdviseRead()

CPLErr GDALRasterBand::AdviseRead ( int  nXOff,
int  nYOff,
int  nXSize,
int  nYSize,
int  nBufXSize,
int  nBufYSize,
GDALDataType  eBufType,
char **  papszOptions 
)
virtualinherited

Advise driver of upcoming read requests.

Some GDAL drivers operate more efficiently if they know in advance what set of upcoming read requests will be made. The AdviseRead() method allows an application to notify the driver of the region of interest, and at what resolution the region will be read.

Many drivers just ignore the AdviseRead() call, but it can dramatically accelerate access via some drivers.

Depending on call paths, drivers might receive several calls to AdviseRead() with the same parameters.

Parameters
nXOffThe 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.
nYOffThe 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.
nXSizeThe width of the region of the band to be accessed in pixels.
nYSizeThe height of the region of the band to be accessed in lines.
nBufXSizethe width of the buffer image into which the desired region is to be read, or from which it is to be written.
nBufYSizethe height of the buffer image into which the desired region is to be read, or from which it is to be written.
eBufTypethe 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.
papszOptionsa list of name=value strings with special control options. Normally this is NULL.
Returns
CE_Failure if the request is invalid and CE_None if it works or is ignored.

◆ AsMDArray()

std::shared_ptr< GDALMDArray > GDALRasterBand::AsMDArray ( ) const
inherited

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.

This is the same as the C function GDALRasterBandAsMDArray().

The "reverse" method is GDALMDArray::AsClassicDataset().

Returns
a new array, or nullptr.
Since
GDAL 3.1

◆ BuildMetadataDomainList()

char ** GDALMajorObject::BuildMetadataDomainList ( char **  papszList,
int  bCheckNonEmpty,
  ... 
)
protectedinherited

Helper function for custom implementations of GetMetadataDomainList()

Parameters
papszListinitial list of domains. May be NULL. Will become invalid after function call (use return value)
bCheckNonEmptyif TRUE, each candidate domain will be tested to be non empty
...NULL terminated variadic list of candidate domains.
Returns
NULL or a string list. Must be freed with CSLDestroy()
Since
GDAL 1.11

◆ BuildOverviews()

CPLErr GDALRasterBand::BuildOverviews ( const char *  pszResampling,
int  nOverviews,
const int *  panOverviewList,
GDALProgressFunc  pfnProgress,
void *  pProgressData,
CSLConstList  papszOptions 
)
virtualinherited

If the operation is unsupported for the indicated dataset, then CE_Failure is returned, and CPLGetLastErrorNo() will return CPLE_NotSupported.

WARNING: It is not possible to build overviews for a single band in TIFF format, and thus this method does not work for TIFF format, or any formats that use the default overview building in TIFF format. Instead it is necessary to build overviews on the dataset as a whole using GDALDataset::BuildOverviews(). That makes this method pretty useless from a practical point of view.

Parameters
pszResamplingone of "NEAREST", "GAUSS", "CUBIC", "AVERAGE", "MODE", "AVERAGE_MAGPHASE" "RMS" or "NONE" controlling the downsampling method applied.
nOverviewsnumber of overviews to build.
panOverviewListthe list of overview decimation factors to build.
pfnProgressa function to call to report progress, or NULL.
pProgressDataapplication data to pass to the progress function.
papszOptions(GDAL >= 3.6) NULL terminated list of options as key=value pairs, or NULL
Returns
CE_None on success or CE_Failure if the operation doesn't work.

◆ ComputeRasterMinMax()

CPLErr GDALRasterBand::ComputeRasterMinMax ( int  bApproxOK,
double *  adfMinMax 
)
virtualinherited

Compute the min/max values for a band.

If approximate is OK, then the band's GetMinimum()/GetMaximum() will be trusted. If it doesn't work, a subsample of blocks will be read to get an approximate min/max. If the band has a nodata value it will be excluded from the minimum and maximum.

If bApprox is FALSE, then all pixels will be read and used to compute an exact range.

This method is the same as the C function GDALComputeRasterMinMax().

Parameters
bApproxOKTRUE if an approximate (faster) answer is OK, otherwise FALSE.
adfMinMaxthe array in which the minimum (adfMinMax[0]) and the maximum (adfMinMax[1]) are returned.
Returns
CE_None on success or CE_Failure on failure.

◆ ComputeStatistics()

CPLErr GDALRasterBand::ComputeStatistics ( int  bApproxOK,
double *  pdfMin,
double *  pdfMax,
double *  pdfMean,
double *  pdfStdDev,
GDALProgressFunc  pfnProgress,
void *  pProgressData 
)
virtualinherited

Compute image statistics.

Returns the minimum, maximum, mean and standard deviation of all pixel values in this band. If approximate statistics are sufficient, the bApproxOK flag can be set to true in which case overviews, or a subset of image tiles may be used in computing the statistics.

Once computed, the statistics will generally be "set" back on the raster band using SetStatistics().

Cached statistics can be cleared with GDALDataset::ClearStatistics().

This method is the same as the C function GDALComputeRasterStatistics().

Parameters
bApproxOKIf TRUE statistics may be computed based on overviews or a subset of all tiles.
pdfMinLocation into which to load image minimum (may be NULL).
pdfMaxLocation into which to load image maximum (may be NULL).-
pdfMeanLocation into which to load image mean (may be NULL).
pdfStdDevLocation into which to load image standard deviation (may be NULL).
pfnProgressa function to call to report progress, or NULL.
pProgressDataapplication data to pass to the progress function.
Returns
CE_None on success, or CE_Failure if an error occurs or processing is terminated by the user.

◆ CreateMaskBand()

CPLErr GDALRasterBand::CreateMaskBand ( int  nFlagsIn)
virtualinherited

Adds a mask band to the current band.

The default implementation of the CreateMaskBand() method is implemented based on similar rules to the .ovr handling implemented using the GDALDefaultOverviews object. A TIFF file with the extension .msk will be created with the same basename as the original file, and it will have as many bands as the original image (or just one for GMF_PER_DATASET). The mask images will be deflate compressed tiled images with the same block size as the original image if possible. It will have INTERNAL_MASK_FLAGS_xx metadata items set at the dataset level, where xx matches the band number of a band of the main dataset. The value of those items will be the one of the nFlagsIn parameter.

Note that if you got a mask band with a previous call to GetMaskBand(), it might be invalidated by CreateMaskBand(). So you have to call GetMaskBand() again.

This method is the same as the C function GDALCreateMaskBand().

Since
GDAL 1.5.0
Parameters
nFlagsIn0 or combination of GMF_PER_DATASET / GMF_ALPHA.
Returns
CE_None on success or CE_Failure on an error.
See also
https://gdal.org/development/rfc/rfc15_nodatabitmask.html
GDALDataset::CreateMaskBand()

◆ DeleteNoDataValue()

CPLErr GDALPamRasterBand::DeleteNoDataValue ( )
overridevirtual

Remove the no data value for this band.

This method is the same as the C function GDALDeleteRasterNoDataValue().

Returns
CE_None on success, or CE_Failure on failure. If unsupported by the driver, CE_Failure is returned by no error message will have been emitted.
Since
GDAL 2.1

Reimplemented from GDALRasterBand.

◆ DropCache()

CPLErr GDALRasterBand::DropCache ( )
virtualinherited

Drop raster data cache : data in cache will be lost.

This call will recover memory used to cache data blocks for this raster band, and ensure that new requests are referred to the underlying driver.

This method is the same as the C function GDALDropRasterCache().

Returns
CE_None on success.
Since
3.9

◆ Fill()

CPLErr GDALRasterBand::Fill ( double  dfRealValue,
double  dfImaginaryValue = 0 
)
virtualinherited

Fill this band with a constant value.

GDAL makes no guarantees about what values pixels in newly created files are set to, so this method can be used to clear a band to a specified "default" value. The fill value is passed in as a double but this will be converted to the underlying type before writing to the file. An optional second argument allows the imaginary component of a complex constant value to be specified.

This method is the same as the C function GDALFillRaster().

Parameters
dfRealValueReal component of fill value
dfImaginaryValueImaginary component of fill value, defaults to zero
Returns
CE_Failure if the write fails, otherwise CE_None

◆ FlushBlock()

CPLErr GDALRasterBand::FlushBlock ( int  nXBlockOff,
int  nYBlockOff,
int  bWriteDirtyBlock = TRUE 
)
inherited

Flush a block out of the block cache.

Parameters
nXBlockOffblock x offset
nYBlockOffblocky offset
bWriteDirtyBlockwhether the block should be written to disk if dirty.
Returns
CE_None in case of success, an error code otherwise.

◆ FlushCache()

CPLErr GDALRasterBand::FlushCache ( bool  bAtClosing = false)
virtualinherited

Flush raster data cache.

This call will recover memory used to cache data blocks for this raster band, and ensure that new requests are referred to the underlying driver.

This method is the same as the C function GDALFlushRasterCache().

Parameters
bAtClosingWhether this is called from a GDALDataset destructor
Returns
CE_None on success.

◆ FromHandle()

static GDALRasterBand * GDALRasterBand::FromHandle ( GDALRasterBandH  hBand)
inlinestaticinherited

Convert a GDALRasterBandH to a GDALRasterBand*.

Since
GDAL 2.3

◆ GetAccess()

GDALAccess GDALRasterBand::GetAccess ( )
inherited

Find out if we have update permission for this band.

This method is the same as the C function GDALGetRasterAccess().

Returns
Either GA_Update or GA_ReadOnly.

◆ GetActualBlockSize()

CPLErr GDALRasterBand::GetActualBlockSize ( int  nXBlockOff,
int  nYBlockOff,
int *  pnXValid,
int *  pnYValid 
)
inherited

Fetch the actual block size for a given block offset.

Handles partial blocks at the edges of the raster and returns the true number of pixels

Parameters
nXBlockOffthe horizontal block offset for which to calculate the number of valid pixels, with zero indicating the left most block, 1 the next block and so forth.
nYBlockOffthe vertical block offset, with zero indicating the top most block, 1 the next block and so forth.
pnXValidpointer to an integer in which the number of valid pixels in the x direction will be stored
pnYValidpointer to an integer in which the number of valid pixels in the y direction will be stored
Returns
CE_None if the input parameters are valid, CE_Failure otherwise
Since
GDAL 2.2

◆ GetBand()

int GDALRasterBand::GetBand ( )
inherited

Fetch the band number.

This method returns the band that this GDALRasterBand objects represents within its dataset. This method may return a value of 0 to indicate GDALRasterBand objects without an apparently relationship to a dataset, such as GDALRasterBands serving as overviews.

This method is the same as the C function GDALGetBandNumber().

Returns
band number (1+) or 0 if the band number isn't known.

◆ GetBlockSize()

void GDALRasterBand::GetBlockSize ( int *  pnXSize,
int *  pnYSize 
)
inherited

Fetch the "natural" block size of this band.

GDAL contains a concept of the natural block size of rasters so that applications can organized data access efficiently for some file formats. The natural block size is the block size that is most efficient for accessing the format. For many formats this is simple a whole scanline in which case *pnXSize is set to GetXSize(), and *pnYSize is set to 1.

However, for tiled images this will typically be the tile size.

Note that the X and Y block sizes don't have to divide the image size evenly, meaning that right and bottom edge blocks may be incomplete. See ReadBlock() for an example of code dealing with these issues.

This method is the same as the C function GDALGetBlockSize().

Parameters
pnXSizeinteger to put the X block size into or NULL.
pnYSizeinteger to put the Y block size into or NULL.

◆ GetCategoryNames()

char ** GDALPamRasterBand::GetCategoryNames ( )
overridevirtual

Fetch the list of category names for this raster.

The return list is a "StringList" in the sense of the CPL functions. That is a NULL terminated array of strings. Raster values without associated names will have an empty string in the returned list. The first entry in the list is for raster values of zero, and so on.

The returned stringlist should not be altered or freed by the application. It may change on the next GDAL call, so please copy it if it is needed for any period of time.

This method is the same as the C function GDALGetRasterCategoryNames().

Returns
list of names, or NULL if none.

Reimplemented from GDALRasterBand.

◆ GetColorInterpretation()

GDALColorInterp GDALPamRasterBand::GetColorInterpretation ( )
overridevirtual

How should this band be interpreted as color?

GCI_Undefined is returned when the format doesn't know anything about the color interpretation.

This method is the same as the C function GDALGetRasterColorInterpretation().

Returns
color interpretation value for band.

Reimplemented from GDALRasterBand.

◆ GetColorTable()

GDALColorTable * GDALPamRasterBand::GetColorTable ( )
overridevirtual

Fetch the color table associated with band.

If there is no associated color table, the return result is NULL. The returned color table remains owned by the GDALRasterBand, and can't be depended on for long, nor should it ever be modified by the caller.

This method is the same as the C function GDALGetRasterColorTable().

Returns
internal color table, or NULL.

Reimplemented from GDALRasterBand.

◆ GetDataCoverageStatus()

int GDALRasterBand::GetDataCoverageStatus ( int  nXOff,
int  nYOff,
int  nXSize,
int  nYSize,
int  nMaskFlagStop = 0,
double *  pdfDataPct = nullptr 
)
inherited

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 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.

See also
GDALGetDataCoverageStatus()
Parameters
nXOffThe 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.
nYOffThe 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.
nXSizeThe width of the region of the band to be queried in pixels.
nYSizeThe height of the region of the band to be queried in lines.
nMaskFlagStop0, 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.
pdfDataPctOptional 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.
Returns
a binary-or'ed combination of possible values GDAL_DATA_COVERAGE_STATUS_UNIMPLEMENTED, GDAL_DATA_COVERAGE_STATUS_DATA and GDAL_DATA_COVERAGE_STATUS_EMPTY
Note
Added in GDAL 2.2

◆ GetDataset()

GDALDataset * GDALRasterBand::GetDataset ( )
inherited

Fetch the owning dataset handle.

Note that some GDALRasterBands are not considered to be a part of a dataset, such as overviews or other "freestanding" bands.

This method is the same as the C function GDALGetBandDataset().

Returns
the pointer to the GDALDataset to which this band belongs, or NULL if this cannot be determined.

◆ GetDefaultHistogram()

CPLErr GDALPamRasterBand::GetDefaultHistogram ( double *  pdfMin,
double *  pdfMax,
int *  pnBuckets,
GUIntBig **  ppanHistogram,
int  bForce,
GDALProgressFunc  pfnProgress,
void *  pProgressData 
)
overridevirtual

Fetch default raster histogram.

The default method in GDALRasterBand will compute a default histogram. This method is overridden by derived classes (such as GDALPamRasterBand, VRTDataset, HFADataset...) that may be able to fetch efficiently an already stored histogram.

This method is the same as the C functions GDALGetDefaultHistogram() and GDALGetDefaultHistogramEx().

Parameters
pdfMinpointer to double value that will contain the lower bound of the histogram.
pdfMaxpointer to double value that will contain the upper bound of the histogram.
pnBucketspointer to int value that will contain the number of buckets in *ppanHistogram.
ppanHistogrampointer to array into which the histogram totals are placed. To be freed with VSIFree
bForceTRUE to force the computation. If FALSE and no default histogram is available, the method will return CE_Warning
pfnProgressfunction to report progress to completion.
pProgressDataapplication data to pass to pfnProgress.
Returns
CE_None on success, CE_Failure if something goes wrong, or CE_Warning if no default histogram is available.

Reimplemented from GDALRasterBand.

◆ GetDefaultRAT()

GDALRasterAttributeTable * GDALPamRasterBand::GetDefaultRAT ( )
overridevirtual

Fetch default Raster Attribute Table.

A RAT will be returned if there is a default one associated with the band, otherwise NULL is returned. The returned RAT is owned by the band and should not be deleted by the application.

This method is the same as the C function GDALGetDefaultRAT().

Returns
NULL, or a pointer to an internal RAT owned by the band.

Reimplemented from GDALRasterBand.

◆ GetDescription()

const char * GDALMajorObject::GetDescription ( ) const
virtualinherited

Fetch object description.

The semantics of the returned description are specific to the derived type. For GDALDatasets it is the dataset name. For GDALRasterBands it is actually a description (if supported) or "".

This method is the same as the C function GDALGetDescription().

Returns
non-null pointer to internal description string.

◆ GetHistogram()

CPLErr GDALPamRasterBand::GetHistogram ( double  dfMin,
double  dfMax,
int  nBuckets,
GUIntBig panHistogram,
int  bIncludeOutOfRange,
int  bApproxOK,
GDALProgressFunc  pfnProgress,
void *  pProgressData 
)
overridevirtual

Compute raster histogram.

Note that the bucket size is (dfMax-dfMin) / nBuckets.

For example to compute a simple 256 entry histogram of eight bit data, the following would be suitable. The unusual bounds are to ensure that bucket boundaries don't fall right on integer values causing possible errors due to rounding after scaling.

GUIntBig anHistogram[256];
poBand->GetHistogram( -0.5, 255.5, 256, anHistogram, FALSE, FALSE,
GDALDummyProgress, nullptr );
unsigned long long GUIntBig
Large unsigned integer type (generally 64-bit unsigned integer type).
Definition: cpl_port.h:218

Note that setting bApproxOK will generally result in a subsampling of the file, and will utilize overviews if available. It should generally produce a representative histogram for the data that is suitable for use in generating histogram based luts for instance. Generally bApproxOK is much faster than an exactly computed histogram.

This method is the same as the C functions GDALGetRasterHistogram() and GDALGetRasterHistogramEx().

Parameters
dfMinthe lower bound of the histogram.
dfMaxthe upper bound of the histogram.
nBucketsthe number of buckets in panHistogram.
panHistogramarray into which the histogram totals are placed.
bIncludeOutOfRangeif TRUE values below the histogram range will mapped into panHistogram[0], and values above will be mapped into panHistogram[nBuckets-1] otherwise out of range values are discarded.
bApproxOKTRUE if an approximate, or incomplete histogram OK.
pfnProgressfunction to report progress to completion.
pProgressDataapplication data to pass to pfnProgress.
Returns
CE_None on success, or CE_Failure if something goes wrong.

Reimplemented from GDALRasterBand.

◆ GetIndexColorTranslationTo()

unsigned char * GDALRasterBand::GetIndexColorTranslationTo ( GDALRasterBand poReferenceBand,
unsigned char *  pTranslationTable = nullptr,
int *  pApproximateMatching = nullptr 
)
inherited

Compute translation table for color tables.

When the raster band has a palette index, it may be useful to compute the "translation" of this palette to the palette of another band. The translation tries to do exact matching first, and then approximate matching if no exact matching is possible. This method returns a table such that table[i] = j where i is an index of the 'this' rasterband and j the corresponding index for the reference rasterband.

This method is thought as internal to GDAL and is used for drivers like RPFTOC.

The implementation only supports 1-byte palette rasterbands.

Parameters
poReferenceBandthe raster band
pTranslationTablean already allocated translation table (at least 256 bytes), or NULL to let the method allocate it
pApproximateMatchinga pointer to a flag that is set if the matching is approximate. May be NULL.
Returns
a translation table if the two bands are palette index and that they do not match or NULL in other cases. The table must be freed with CPLFree if NULL was passed for pTranslationTable.

◆ GetLockedBlockRef()

GDALRasterBlock * GDALRasterBand::GetLockedBlockRef ( int  nXBlockOff,
int  nYBlockOff,
int  bJustInitialize = FALSE 
)
inherited

Fetch a pointer to an internally cached raster block.

This method will returned the requested block (locked) if it is already in the block cache for the layer. If not, the block will be read from the driver, and placed in the layer block cached, then returned. If an error occurs reading the block from the driver, a NULL value will be returned.

If a non-NULL value is returned, then a lock for the block will have been acquired on behalf of the caller. It is absolutely imperative that the caller release this lock (with GDALRasterBlock::DropLock()) or else severe problems may result.

Note that calling GetLockedBlockRef() on a previously uncached band will enable caching.

Parameters
nXBlockOffthe horizontal block offset, with zero indicating the left most block, 1 the next block and so forth.
nYBlockOffthe vertical block offset, with zero indicating the top most block, 1 the next block and so forth.
bJustInitializeIf TRUE the block will be allocated and initialized, but not actually read from the source. This is useful when it will just be completely set and written back.
Returns
pointer to the block object, or NULL on failure.

◆ GetMaskBand()

GDALRasterBand * GDALRasterBand::GetMaskBand ( )
virtualinherited

Return the mask band associated with the band.

The GDALRasterBand class includes a default implementation of GetMaskBand() that returns one of four default implementations :

  • If a corresponding .msk file exists it will be used for the mask band.
  • If the dataset has a NODATA_VALUES metadata item, an instance of the new GDALNoDataValuesMaskBand class will be returned. GetMaskFlags() will return GMF_NODATA | GMF_PER_DATASET.
    Since
    GDAL 1.6.0
  • If the band has a nodata value set, an instance of the new GDALNodataMaskRasterBand class will be returned. GetMaskFlags() will return GMF_NODATA.
  • If there is no nodata value, but the dataset has an alpha band that seems to apply to this band (specific rules yet to be determined) and that is of type GDT_Byte then that alpha band will be returned, and the flags GMF_PER_DATASET and GMF_ALPHA will be returned in the flags.
  • If neither of the above apply, an instance of the new GDALAllValidRasterBand class will be returned that has 255 values for all pixels. The null flags will return GMF_ALL_VALID.

Note that the GetMaskBand() should always return a GDALRasterBand mask, even if it is only an all 255 mask with the flags indicating GMF_ALL_VALID.

For an external .msk file to be recognized by GDAL, it must be a valid GDAL dataset, with the same name as the main dataset and suffixed with .msk, with either one band (in the GMF_PER_DATASET case), or as many bands as the main dataset. It must have INTERNAL_MASK_FLAGS_xx metadata items set at the dataset level, where xx matches the band number of a band of the main dataset. The value of those items is a combination of the flags GMF_ALL_VALID, GMF_PER_DATASET, GMF_ALPHA and GMF_NODATA. If a metadata item is missing for a band, then the other rules explained above will be used to generate a on-the-fly mask band.

See also
CreateMaskBand() for the characteristics of .msk files created by GDAL.

This method is the same as the C function GDALGetMaskBand().

Returns
a valid mask band.
Since
GDAL 1.5.0
See also
https://gdal.org/development/rfc/rfc15_nodatabitmask.html

◆ GetMaskFlags()

int GDALRasterBand::GetMaskFlags ( )
virtualinherited

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

The GetMaskFlags() method returns an bitwise OR-ed set of status flags with the following available definitions that may be extended in the future:

  • GMF_ALL_VALID(0x01): There are no invalid pixels, all mask values will be
    1. When used this will normally be the only flag set.
  • GMF_PER_DATASET(0x02): The mask band is shared between all bands on the dataset.
  • GMF_ALPHA(0x04): The mask band is actually an alpha band and may have values other than 0 and 255.
  • GMF_NODATA(0x08): Indicates the mask is actually being generated from nodata values. (mutually exclusive of GMF_ALPHA)

The GDALRasterBand class includes a default implementation of GetMaskBand() that returns one of four default implementations :

  • If a corresponding .msk file exists it will be used for the mask band.
  • If the dataset has a NODATA_VALUES metadata item, an instance of the new GDALNoDataValuesMaskBand class will be returned. GetMaskFlags() will return GMF_NODATA | GMF_PER_DATASET.
    Since
    GDAL 1.6.0
  • If the band has a nodata value set, an instance of the new GDALNodataMaskRasterBand class will be returned. GetMaskFlags() will return GMF_NODATA.
  • If there is no nodata value, but the dataset has an alpha band that seems to apply to this band (specific rules yet to be determined) and that is of type GDT_Byte then that alpha band will be returned, and the flags GMF_PER_DATASET and GMF_ALPHA will be returned in the flags.
  • If neither of the above apply, an instance of the new GDALAllValidRasterBand class will be returned that has 255 values for all pixels. The null flags will return GMF_ALL_VALID.

For an external .msk file to be recognized by GDAL, it must be a valid GDAL dataset, with the same name as the main dataset and suffixed with .msk, with either one band (in the GMF_PER_DATASET case), or as many bands as the main dataset. It must have INTERNAL_MASK_FLAGS_xx metadata items set at the dataset level, where xx matches the band number of a band of the main dataset. The value of those items is a combination of the flags GMF_ALL_VALID, GMF_PER_DATASET, GMF_ALPHA and GMF_NODATA. If a metadata item is missing for a band, then the other rules explained above will be used to generate a on-the-fly mask band.

See also
CreateMaskBand() for the characteristics of .msk files created by GDAL.

This method is the same as the C function GDALGetMaskFlags().

Since
GDAL 1.5.0
Returns
a valid mask band.
See also
https://gdal.org/development/rfc/rfc15_nodatabitmask.html

◆ GetMaskValueRange()

GDALMaskValueRange GDALRasterBand::GetMaskValueRange ( ) const
virtualinherited

Returns the range of values that a mask band can take.

Returns
the range of values that a mask band can take.
Since
GDAL 3.5.0

◆ GetMaximum()

double GDALRasterBand::GetMaximum ( int *  pbSuccess = nullptr)
virtualinherited

Fetch the maximum value for this band.

For file formats that don't know this intrinsically, the maximum supported value for the data type will generally be returned.

This method is the same as the C function GDALGetRasterMaximum().

Parameters
pbSuccesspointer to a boolean to use to indicate if the returned value is a tight maximum or not. May be NULL (default).
Returns
the maximum raster value (excluding no data pixels)

◆ GetMetadata()

char ** GDALMajorObject::GetMetadata ( const char *  pszDomain = "")
virtualinherited

Fetch metadata.

The returned string list is owned by the object, and may change at any time. It is formatted as a "Name=value" list with the last pointer value being NULL. Use the CPL StringList functions such as CSLFetchNameValue() to manipulate it.

Note that relatively few formats return any metadata at this time.

This method does the same thing as the C function GDALGetMetadata().

Parameters
pszDomainthe domain of interest. Use "" or NULL for the default domain.
Returns
NULL or a string list.

Reimplemented in GDALPluginDriverProxy, GDALPamDataset, and GDALDataset.

◆ GetMetadataDomainList()

char ** GDALMajorObject::GetMetadataDomainList ( )
virtualinherited

Fetch list of metadata domains.

The returned string list is the list of (non-empty) metadata domains.

This method does the same thing as the C function GDALGetMetadataDomainList().

Returns
NULL or a string list. Must be freed with CSLDestroy()
Since
GDAL 1.11

Reimplemented in GDALDataset.

◆ GetMetadataItem()

const char * GDALRasterBand::GetMetadataItem ( const char *  pszName,
const char *  pszDomain = "" 
)
overridevirtualinherited

Fetch single metadata item.

The C function GDALGetMetadataItem() does the same thing as this method.

Parameters
pszNamethe key for the metadata item to fetch.
pszDomainthe domain to fetch for, use NULL for the default domain.
Returns
NULL on failure to find the key, or a pointer to an internal copy of the value string on success.

Reimplemented from GDALMajorObject.

◆ GetMinimum()

double GDALRasterBand::GetMinimum ( int *  pbSuccess = nullptr)
virtualinherited

Fetch the minimum value for this band.

For file formats that don't know this intrinsically, the minimum supported value for the data type will generally be returned.

This method is the same as the C function GDALGetRasterMinimum().

Parameters
pbSuccesspointer to a boolean to use to indicate if the returned value is a tight minimum or not. May be NULL (default).
Returns
the minimum raster value (excluding no data pixels)

◆ GetMOFlags()

int GDALMajorObject::GetMOFlags ( ) const
inherited

Returns the GMO_ flags.

Returns
flags

◆ GetNoDataValue()

double GDALPamRasterBand::GetNoDataValue ( int *  pbSuccess = nullptr)
overridevirtual

Fetch the no data value for this band.

If there is no out of data value, an out of range value will generally be returned. The no data value for a band is generally a special marker value used to mark pixels that are not valid data. Such pixels should generally not be displayed, nor contribute to analysis operations.

The no data value returned is 'raw', meaning that it has no offset and scale applied.

For rasters of type GDT_Int64 or GDT_UInt64, using this method might be lossy if the nodata value cannot exactly been represented by a double. Use GetNoDataValueAsInt64() or GetNoDataValueAsUInt64() instead.

This method is the same as the C function GDALGetRasterNoDataValue().

Parameters
pbSuccesspointer to a boolean to use to indicate if a value is actually associated with this layer. May be NULL (default).
Returns
the nodata value for this band.

Reimplemented from GDALRasterBand.

◆ GetNoDataValueAsInt64()

int64_t GDALPamRasterBand::GetNoDataValueAsInt64 ( int *  pbSuccess = nullptr)
overridevirtual

Fetch the no data value for this band.

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

If there is no out of data value, an out of range value will generally be returned. The no data value for a band is generally a special marker value used to mark pixels that are not valid data. Such pixels should generally not be displayed, nor contribute to analysis operations.

The no data value returned is 'raw', meaning that it has no offset and scale applied.

This method is the same as the C function GDALGetRasterNoDataValueAsInt64().

Parameters
pbSuccesspointer to a boolean to use to indicate if a value is actually associated with this layer. May be NULL (default).
Returns
the nodata value for this band.
Since
GDAL 3.5

Reimplemented from GDALRasterBand.

◆ GetNoDataValueAsUInt64()

uint64_t GDALPamRasterBand::GetNoDataValueAsUInt64 ( int *  pbSuccess = nullptr)
overridevirtual

Fetch the no data value for this band.

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

If there is no out of data value, an out of range value will generally be returned. The no data value for a band is generally a special marker value used to mark pixels that are not valid data. Such pixels should generally not be displayed, nor contribute to analysis operations.

The no data value returned is 'raw', meaning that it has no offset and scale applied.

This method is the same as the C function GDALGetRasterNoDataValueAsUInt64().

Parameters
pbSuccesspointer to a boolean to use to indicate if a value is actually associated with this layer. May be NULL (default).
Returns
the nodata value for this band.
Since
GDAL 3.5

Reimplemented from GDALRasterBand.

◆ GetOffset()

double GDALPamRasterBand::GetOffset ( int *  pbSuccess = nullptr)
overridevirtual

Fetch the raster value offset.

This value (in combination with the GetScale() value) can be used to transform raw pixel values into the units returned by GetUnitType(). For example this might be used to store elevations in GUInt16 bands with a precision of 0.1, and starting from -100.

Units value = (raw value * scale) + offset

Note that applying scale and offset is of the responsibility of the user, and is not done by methods such as RasterIO() or ReadBlock().

For file formats that don't know this intrinsically a value of zero is returned.

This method is the same as the C function GDALGetRasterOffset().

Parameters
pbSuccesspointer to a boolean to use to indicate if the returned value is meaningful or not. May be NULL (default).
Returns
the raster offset.

Reimplemented from GDALRasterBand.

◆ GetOverview()

GDALRasterBand * GDALRasterBand::GetOverview ( int  i)
virtualinherited

Fetch overview raster band object.

This method is the same as the C function GDALGetOverview().

Parameters
ioverview index between 0 and GetOverviewCount()-1.
Returns
overview GDALRasterBand.

◆ GetOverviewCount()

int GDALRasterBand::GetOverviewCount ( )
virtualinherited

Return the number of overview layers available.

This method is the same as the C function GDALGetOverviewCount().

Returns
overview count, zero if none.

◆ GetRasterDataType()

GDALDataType GDALRasterBand::GetRasterDataType ( void  )
inherited

Fetch the pixel data type for this band.

This method is the same as the C function GDALGetRasterDataType().

Returns
the data type of pixels for this band.

◆ GetRasterSampleOverview()

GDALRasterBand * GDALRasterBand::GetRasterSampleOverview ( GUIntBig  nDesiredSamples)
virtualinherited

Fetch best sampling overview.

Returns the most reduced overview of the given band that still satisfies the desired number of samples. This function can be used with zero as the number of desired samples to fetch the most reduced overview. The same band as was passed in will be returned if it has not overviews, or if none of the overviews have enough samples.

This method is the same as the C functions GDALGetRasterSampleOverview() and GDALGetRasterSampleOverviewEx().

Parameters
nDesiredSamplesthe returned band will have at least this many pixels.
Returns
optimal overview or the band itself.

◆ GetScale()

double GDALPamRasterBand::GetScale ( int *  pbSuccess = nullptr)
overridevirtual

Fetch the raster value scale.

This value (in combination with the GetOffset() value) can be used to transform raw pixel values into the units returned by GetUnitType(). For example this might be used to store elevations in GUInt16 bands with a precision of 0.1, and starting from -100.

Units value = (raw value * scale) + offset

Note that applying scale and offset is of the responsibility of the user, and is not done by methods such as RasterIO() or ReadBlock().

For file formats that don't know this intrinsically a value of one is returned.

This method is the same as the C function GDALGetRasterScale().

Parameters
pbSuccesspointer to a boolean to use to indicate if the returned value is meaningful or not. May be NULL (default).
Returns
the raster scale.

Reimplemented from GDALRasterBand.

◆ GetStatistics()

CPLErr GDALRasterBand::GetStatistics ( int  bApproxOK,
int  bForce,
double *  pdfMin,
double *  pdfMax,
double *  pdfMean,
double *  pdfStdDev 
)
virtualinherited

Fetch image statistics.

Returns the minimum, maximum, mean and standard deviation of all pixel values in this band. If approximate statistics are sufficient, the bApproxOK flag can be set to true in which case overviews, or a subset of image tiles may be used in computing the statistics.

If bForce is FALSE results will only be returned if it can be done quickly (i.e. without scanning the image, typically by using pre-existing STATISTICS_xxx metadata items). If bForce is FALSE and results cannot be returned efficiently, the method will return CE_Warning but no warning will be issued. This is a non-standard use of the CE_Warning return value to indicate "nothing done".

If bForce is TRUE, and results are quickly available without scanning the image, they will be used. If bForce is TRUE and results are not quickly available, GetStatistics() forwards the computation to ComputeStatistics(), which will scan the image.

To always force recomputation of statistics, use ComputeStatistics() instead of this method.

Note that file formats using PAM (Persistent Auxiliary Metadata) services will generally cache statistics in the .pam file allowing fast fetch after the first request.

This method is the same as the C function GDALGetRasterStatistics().

Parameters
bApproxOKIf TRUE statistics may be computed based on overviews or a subset of all tiles.
bForceIf FALSE statistics will only be returned if it can be done without rescanning the image. If TRUE, statistics computation will be forced if pre-existing values are not quickly available.
pdfMinLocation into which to load image minimum (may be NULL).
pdfMaxLocation into which to load image maximum (may be NULL).-
pdfMeanLocation into which to load image mean (may be NULL).
pdfStdDevLocation into which to load image standard deviation (may be NULL).
Returns
CE_None on success, CE_Warning if no values returned, CE_Failure if an error occurs.

◆ GetSuggestedBlockAccessPattern()

GDALSuggestedBlockAccessPattern GDALRasterBand::GetSuggestedBlockAccessPattern ( ) const
virtualinherited

Return the suggested/most efficient access pattern to blocks (for read operations).

While all GDAL drivers have to expose a block size, not all can guarantee efficient random access (GSBAP_RANDOM) to any block. Some drivers for example decompress sequentially a compressed stream from top raster to bottom (GSBAP_TOP_TO_BOTTOM), in which case best performance will be achieved while reading blocks in that order. (accessing blocks in random access in such rasters typically causes the decoding to be re-initialized from the start if accessing blocks in a non-sequential order)

The base implementation returns GSBAP_UNKNOWN, which can also be explicitly returned by drivers that expose a somewhat artificial block size, because they can extract any part of a raster, but in a rather inefficient way.

The GSBAP_LARGEST_CHUNK_POSSIBLE value can be combined as a logical bitmask with other enumeration values (GSBAP_UNKNOWN, GSBAP_RANDOM, GSBAP_TOP_TO_BOTTOM, GSBAP_BOTTOM_TO_TOP). When a driver sets this flag, the most efficient strategy is to read as many pixels as possible in the less RasterIO() operations.

The return of this method is for example used to determine the swath size used by GDALDatasetCopyWholeRaster() and GDALRasterBandCopyWholeRaster().

Since
GDAL 3.6

◆ GetUnitType()

const char * GDALPamRasterBand::GetUnitType ( )
overridevirtual

Return raster unit type.

Return a name for the units of this raster's values. For instance, it might be "m" for an elevation model in meters, or "ft" for feet. If no units are available, a value of "" will be returned. The returned string should not be modified, nor freed by the calling application.

This method is the same as the C function GDALGetRasterUnitType().

Returns
unit name string.

Reimplemented from GDALRasterBand.

◆ GetVirtualMemAuto()

CPLVirtualMem * GDALRasterBand::GetVirtualMemAuto ( GDALRWFlag  eRWFlag,
int *  pnPixelSpace,
GIntBig pnLineSpace,
char **  papszOptions 
)
virtualinherited

Create a CPLVirtualMem object from a GDAL raster band object.

Only supported on Linux and Unix systems with mmap() for now.

This method allows creating a virtual memory object for a GDALRasterBand, that exposes the whole image data as a virtual array.

The default implementation relies on GDALRasterBandGetVirtualMem(), but specialized implementation, such as for raw files, may also directly use mechanisms of the operating system to create a view of the underlying file into virtual memory ( CPLVirtualMemFileMapNew() )

At the time of writing, the GeoTIFF driver and "raw" drivers (EHdr, ...) offer a specialized implementation with direct file mapping, provided that some requirements are met :

  • for all drivers, the dataset must be backed by a "real" file in the file system, and the byte ordering of multi-byte datatypes (Int16, etc.) must match the native ordering of the CPU.
  • in addition, for the GeoTIFF driver, the GeoTIFF file must be uncompressed, scanline oriented (i.e. not tiled). Strips must be organized in the file in sequential order, and be equally spaced (which is generally the case). Only power-of-two bit depths are supported (8 for GDT_Bye, 16 for GDT_Int16/GDT_UInt16, 32 for GDT_Float32 and 64 for GDT_Float64)

The pointer returned 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 type matching GDALGetRasterDataType(), the element of image coordinates (x, y) can be accessed with *(base_type*) ((GByte*)p + x * *pnPixelSpace + y * *pnLineSpace)

This method is the same as the C GDALGetVirtualMemAuto() function.

Parameters
eRWFlagEither GF_Read to read the band, or GF_Write to read/write the band.
pnPixelSpaceOutput parameter giving the byte offset from the start of one pixel value in the buffer to the start of the next pixel value within a scanline.
pnLineSpaceOutput parameter giving the byte offset from the start of one scanline in the buffer to the start of the next.
papszOptionsNULL terminated list of options. If a specialized implementation exists, defining USE_DEFAULT_IMPLEMENTATION=YES will cause the default implementation to be used. On the contrary, starting with GDAL 2.2, defining USE_DEFAULT_IMPLEMENTATION=NO will prevent the default implementation from being used (thus only allowing efficient implementations to be used). When requiring or falling back to the default implementation, the following options are available : CACHE_SIZE (in bytes, defaults to 40 MB), PAGE_SIZE_HINT (in bytes), SINGLE_THREAD ("FALSE" / "TRUE", defaults to FALSE)
Returns
a virtual memory object that must be unreferenced by CPLVirtualMemFree(), or NULL in case of failure.
Since
GDAL 1.11

◆ GetXSize()

int GDALRasterBand::GetXSize ( )
inherited

Fetch XSize of raster.

This method is the same as the C function GDALGetRasterBandXSize().

Returns
the width in pixels of this band.

◆ GetYSize()

int GDALRasterBand::GetYSize ( )
inherited

Fetch YSize of raster.

This method is the same as the C function GDALGetRasterBandYSize().

Returns
the height in pixels of this band.

◆ HasArbitraryOverviews()

int GDALRasterBand::HasArbitraryOverviews ( )
virtualinherited

Check for arbitrary overviews.

This returns TRUE if the underlying datastore can compute arbitrary overviews efficiently, such as is the case with OGDI over a network. Datastores with arbitrary overviews don't generally have any fixed overviews, but the RasterIO() method can be used in downsampling mode to get overview data efficiently.

This method is the same as the C function GDALHasArbitraryOverviews(),

Returns
TRUE if arbitrary overviews available (efficiently), otherwise FALSE.

◆ IGetDataCoverageStatus()

int GDALRasterBand::IGetDataCoverageStatus ( int  nXOff,
int  nYOff,
int  nXSize,
int  nYSize,
int  nMaskFlagStop,
double *  pdfDataPct 
)
protectedvirtualinherited

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 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.

See also
GDALGetDataCoverageStatus()
Parameters
nXOffThe 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.
nYOffThe 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.
nXSizeThe width of the region of the band to be queried in pixels.
nYSizeThe height of the region of the band to be queried in lines.
nMaskFlagStop0, 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.
pdfDataPctOptional 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.
Returns
a binary-or'ed combination of possible values GDAL_DATA_COVERAGE_STATUS_UNIMPLEMENTED, GDAL_DATA_COVERAGE_STATUS_DATA and GDAL_DATA_COVERAGE_STATUS_EMPTY
Note
Added in GDAL 2.2

◆ IRasterIO()

CPLErr GDALRasterBand::IRasterIO ( GDALRWFlag  eRWFlag,
int  nXOff,
int  nYOff,
int  nXSize,
int  nYSize,
void *  pData,
int  nBufXSize,
int  nBufYSize,
GDALDataType  eBufType,
GSpacing  nPixelSpace,
GSpacing  nLineSpace,
GDALRasterIOExtraArg psExtraArg 
)
protectedvirtualinherited

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

This method allows reading a region of a GDALRasterBand into a buffer, or writing data from a buffer into a region of a GDALRasterBand. It automatically takes care of data type translation if the data type (eBufType) of the buffer is different than that of the GDALRasterBand. The method also takes care of image decimation / replication if the buffer size (nBufXSize x nBufYSize) is different than the size of the region being accessed (nXSize x nYSize).

The nPixelSpace and nLineSpace parameters allow reading into or writing from unusually organized buffers. This is primarily used for buffers containing more than one bands raster data in interleaved format.

Some formats may efficiently implement decimation into a buffer by reading from lower resolution overview images. The logic of the default implementation in the base class GDALRasterBand is the following one. It computes a target_downscaling_factor from the window of interest and buffer size which is min(nXSize/nBufXSize, nYSize/nBufYSize). It then walks through overviews and will select the first one whose downscaling factor is greater than target_downscaling_factor / 1.2.

Let's assume we have overviews at downscaling factors 2, 4 and 8. The relationship between target_downscaling_factor and the select overview level is the following one:

target_downscaling_factor selected_overview
]0, 2 / 1.2] full resolution band
]2 / 1.2, 4 / 1.2] 2x downsampled band
]4 / 1.2, 8 / 1.2] 4x downsampled band
]8 / 1.2, infinity[ 8x downsampled band

Note that starting with GDAL 3.9, this 1.2 oversampling factor can be modified by setting the GDAL_OVERVIEW_OVERSAMPLING_THRESHOLD configuration option. Also note that starting with GDAL 3.9, when the resampling algorithm specified in psExtraArg->eResampleAlg is different from GRIORA_NearestNeighbour, this oversampling threshold defaults to 1. Consequently if there are overviews of downscaling factor 2, 4 and 8, and the desired downscaling factor is 7.99, the overview of factor 4 will be selected for a non nearest resampling.

For highest performance full resolution data access, read and write on "block boundaries" as returned by GetBlockSize(), or use the ReadBlock() and WriteBlock() methods.

This method is the same as the C GDALRasterIO() or GDALRasterIOEx() functions.

Parameters
eRWFlagEither GF_Read to read a region of data, or GF_Write to write a region of data.
nXOffThe 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.
nYOffThe 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.
nXSizeThe width of the region of the band to be accessed in pixels.
nYSizeThe height of the region of the band to be accessed in lines.
pDataThe buffer into which the data should be read, or from which it should be written. This buffer must contain at least nBufXSize * nBufYSize 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. Note that even with eRWFlag==GF_Write, the content of the buffer might be temporarily modified during the execution of this method (and eventually restored back to its original content), so it is not safe to use a buffer stored in a read-only section of the calling program.
nBufXSizethe width of the buffer image into which the desired region is to be read, or from which it is to be written.
nBufYSizethe height of the buffer image into which the desired region is to be read, or from which it is to be written.
eBufTypethe 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.
nPixelSpaceThe 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.
nLineSpaceThe byte offset from the start of one scanline in pData to the start of the next. If defaulted (0) the size of the datatype eBufType * nBufXSize is used.
psExtraArg(new in GDAL 2.0) pointer to a GDALRasterIOExtraArg structure with additional arguments to specify resampling and progress callback, or NULL for default behavior. The GDAL_RASTERIO_RESAMPLING configuration option can also be defined to override the default resampling to one of BILINEAR, CUBIC, CUBICSPLINE, LANCZOS, AVERAGE or MODE.
Returns
CE_Failure if the access fails, otherwise CE_None.

◆ IReadBlock()

GDALRasterBand::IReadBlock ( int  nBlockXOff,
int  nBlockYOff,
void *  pData 
)
protectedpure virtualinherited

Default internal implementation ... to be overridden by subclasses that support reading.

Parameters
nBlockXOffBlock X Offset
nBlockYOffBlock Y Offset
pDataPixel buffer into which to place read data.
Returns
CE_None on success or CE_Failure on an error.

◆ IsMaskBand()

bool GDALRasterBand::IsMaskBand ( ) const
virtualinherited

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 method is the same as the C function GDALIsMaskBand().

Returns
true if the band is a mask band.
See also
GDALDataset::CreateMaskBand()
Since
GDAL 3.5.0

◆ IWriteBlock()

CPLErr GDALRasterBand::IWriteBlock ( int  nBlockXOff,
int  nBlockYOff,
void *  pData 
)
protectedvirtualinherited

Write a block of data.

Default internal implementation ... to be overridden by subclasses that support writing.

Parameters
nBlockXOffBlock X Offset
nBlockYOffBlock Y Offset
pDataPixel buffer to write
Returns
CE_None on success or CE_Failure on an error.

◆ RasterIO()

CPLErr GDALRasterBand::RasterIO ( GDALRWFlag  eRWFlag,
int  nXOff,
int  nYOff,
int  nXSize,
int  nYSize,
void *  pData,
int  nBufXSize,
int  nBufYSize,
GDALDataType  eBufType,
GSpacing  nPixelSpace,
GSpacing  nLineSpace,
GDALRasterIOExtraArg psExtraArg 
)
inherited

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

This method allows reading a region of a GDALRasterBand into a buffer, or writing data from a buffer into a region of a GDALRasterBand. It automatically takes care of data type translation if the data type (eBufType) of the buffer is different than that of the GDALRasterBand. The method also takes care of image decimation / replication if the buffer size (nBufXSize x nBufYSize) is different than the size of the region being accessed (nXSize x nYSize).

The nPixelSpace and nLineSpace parameters allow reading into or writing from unusually organized buffers. This is primarily used for buffers containing more than one bands raster data in interleaved format.

Some formats may efficiently implement decimation into a buffer by reading from lower resolution overview images. The logic of the default implementation in the base class GDALRasterBand is the following one. It computes a target_downscaling_factor from the window of interest and buffer size which is min(nXSize/nBufXSize, nYSize/nBufYSize). It then walks through overviews and will select the first one whose downscaling factor is greater than target_downscaling_factor / 1.2.

Let's assume we have overviews at downscaling factors 2, 4 and 8. The relationship between target_downscaling_factor and the select overview level is the following one:

target_downscaling_factor selected_overview
]0, 2 / 1.2] full resolution band
]2 / 1.2, 4 / 1.2] 2x downsampled band
]4 / 1.2, 8 / 1.2] 4x downsampled band
]8 / 1.2, infinity[ 8x downsampled band

For highest performance full resolution data access, read and write on "block boundaries" as returned by GetBlockSize(), or use the ReadBlock() and WriteBlock() methods.

This method is the same as the C GDALRasterIO() or GDALRasterIOEx() functions.

Parameters
eRWFlagEither GF_Read to read a region of data, or GF_Write to write a region of data.
nXOffThe 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.
nYOffThe 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.
nXSizeThe width of the region of the band to be accessed in pixels.
nYSizeThe height of the region of the band to be accessed in lines.
[in,out]pDataThe buffer into which the data should be read, or from which it should be written. This buffer must contain at least nBufXSize * nBufYSize 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.
nBufXSizethe width of the buffer image into which the desired region is to be read, or from which it is to be written.
nBufYSizethe height of the buffer image into which the desired region is to be read, or from which it is to be written.
eBufTypethe 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.
nPixelSpaceThe 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.
nLineSpaceThe byte offset from the start of one scanline in pData to the start of the next. If defaulted (0) the size of the datatype eBufType * nBufXSize is used.
[in]psExtraArg(new in GDAL 2.0) pointer to a GDALRasterIOExtraArg structure with additional arguments to specify resampling and progress callback, or NULL for default behavior. The GDAL_RASTERIO_RESAMPLING configuration option can also be defined to override the default resampling to one of BILINEAR, CUBIC, CUBICSPLINE, LANCZOS, AVERAGE or MODE.
Returns
CE_Failure if the access fails, otherwise CE_None.

◆ ReadBlock()

CPLErr GDALRasterBand::ReadBlock ( int  nXBlockOff,
int  nYBlockOff,
void *  pImage 
)
inherited

Read a block of image data efficiently.

This method accesses a "natural" block from the raster band without resampling, or data type conversion. For a more generalized, but potentially less efficient access use RasterIO().

This method is the same as the C GDALReadBlock() function.

See the GetLockedBlockRef() method for a way of accessing internally cached block oriented data without an extra copy into an application buffer.

The following code would efficiently compute a histogram of eight bit raster data. Note that the final block may be partial ... data beyond the edge of the underlying raster band in these edge blocks is of an undetermined value.

CPLErr GetHistogram( GDALRasterBand *poBand, GUIntBig *panHistogram )
{
memset( panHistogram, 0, sizeof(GUIntBig) * 256 );
int nXBlockSize, nYBlockSize;
poBand->GetBlockSize( &nXBlockSize, &nYBlockSize );
int nXBlocks = (poBand->GetXSize() + nXBlockSize - 1) / nXBlockSize;
int nYBlocks = (poBand->GetYSize() + nYBlockSize - 1) / nYBlockSize;
GByte *pabyData = (GByte *) CPLMalloc(nXBlockSize * nYBlockSize);
for( int iYBlock = 0; iYBlock < nYBlocks; iYBlock++ )
{
for( int iXBlock = 0; iXBlock < nXBlocks; iXBlock++ )
{
int nXValid, nYValid;
poBand->ReadBlock( iXBlock, iYBlock, pabyData );
// Compute the portion of the block that is valid
// for partial edge blocks.
poBand->GetActualBlockSize(iXBlock, iYBlock, &nXValid, &nYValid)
// Collect the histogram counts.
for( int iY = 0; iY < nYValid; iY++ )
{
for( int iX = 0; iX < nXValid; iX++ )
{
panHistogram[pabyData[iX + iY * nXBlockSize]] += 1;
}
}
}
}
}
CPLErr GetHistogram(double dfMin, double dfMax, int nBuckets, GUIntBig *panHistogram, int bIncludeOutOfRange, int bApproxOK, GDALProgressFunc, void *pProgressData) override
Compute raster histogram.
Definition: gdalpamrasterband.cpp:1389
A single raster band (or channel).
Definition: gdal_priv.h:1467
CPLErr ReadBlock(int, int, void *)
Read a block of image data efficiently.
Definition: gdalrasterband.cpp:566
int GetXSize()
Fetch XSize of raster.
Definition: gdalrasterband.cpp:3215
CPLErr GetActualBlockSize(int, int, int *, int *)
Fetch the actual block size for a given block offset.
Definition: gdalrasterband.cpp:812
int GetYSize()
Fetch YSize of raster.
Definition: gdalrasterband.cpp:3252
GDALDataType GetRasterDataType(void)
Fetch the pixel data type for this band.
Definition: gdalrasterband.cpp:915
void GetBlockSize(int *, int *)
Fetch the "natural" block size of this band.
Definition: gdalrasterband.cpp:966
#define CPLAssert(expr)
Assert on an expression.
Definition: cpl_error.h:216
CPLErr
Error category.
Definition: cpl_error.h:53
unsigned char GByte
Unsigned byte type.
Definition: cpl_port.h:185
@ GDT_Byte
Definition: gdal.h:66
Parameters
nXBlockOffthe horizontal block offset, with zero indicating the left most block, 1 the next block and so forth.
nYBlockOffthe vertical block offset, with zero indicating the top most block, 1 the next block and so forth.
pImagethe buffer into which the data will be read. The buffer must be large enough to hold GetBlockXSize()*GetBlockYSize() words of type GetRasterDataType().
Returns
CE_None on success or CE_Failure on an error.

◆ ReportError()

void GDALRasterBand::ReportError ( CPLErr  eErrClass,
CPLErrorNum  err_no,
const char *  fmt,
  ... 
)
inherited

Emits an error related to a raster band.

This function is a wrapper for regular CPLError(). The only difference with CPLError() is that it prepends the error message with the dataset name and the band number.

Parameters
eErrClassone of CE_Warning, CE_Failure or CE_Fatal.
err_nothe error number (CPLE_*) from cpl_error.h.
fmta printf() style format string. Any additional arguments will be treated as arguments to fill in this format in a manner similar to printf().
Since
GDAL 1.9.0

◆ SetCategoryNames()

CPLErr GDALPamRasterBand::SetCategoryNames ( char **  papszNames)
overridevirtual

Set the category names for this band.

See the GetCategoryNames() method for more on the interpretation of category names.

This method is the same as the C function GDALSetRasterCategoryNames().

Parameters
papszNamesthe NULL terminated StringList of category names. May be NULL to just clear the existing list.
Returns
CE_None on success of CE_Failure on failure. If unsupported by the driver CE_Failure is returned, but no error message is reported.

Reimplemented from GDALRasterBand.

◆ SetColorInterpretation()

CPLErr GDALPamRasterBand::SetColorInterpretation ( GDALColorInterp  eColorInterp)
overridevirtual

Set color interpretation of a band.

This method is the same as the C function GDALSetRasterColorInterpretation().

Parameters
eColorInterpthe new color interpretation to apply to this band.
Returns
CE_None on success or CE_Failure if method is unsupported by format.

Reimplemented from GDALRasterBand.

◆ SetColorTable()

CPLErr GDALPamRasterBand::SetColorTable ( GDALColorTable poCT)
overridevirtual

Set the raster color table.

The driver will make a copy of all desired data in the colortable. It remains owned by the caller after the call.

This method is the same as the C function GDALSetRasterColorTable().

Parameters
poCTthe color table to apply. This may be NULL to clear the color table (where supported).
Returns
CE_None on success, or CE_Failure on failure. If the action is unsupported by the driver, a value of CE_Failure is returned, but no error is issued.

Reimplemented from GDALRasterBand.

◆ SetDefaultHistogram()

CPLErr GDALPamRasterBand::SetDefaultHistogram ( double  dfMin,
double  dfMax,
int  nBuckets,
GUIntBig panHistogram 
)
overridevirtual

Set default histogram.

This method is the same as the C function GDALSetDefaultHistogram() and GDALSetDefaultHistogramEx()

Reimplemented from GDALRasterBand.

◆ SetDefaultRAT()

CPLErr GDALPamRasterBand::SetDefaultRAT ( const GDALRasterAttributeTable poRAT)
overridevirtual

Set default Raster Attribute Table.

Associates a default RAT with the band. If not implemented for the format a CPLE_NotSupported error will be issued. If successful a copy of the RAT is made, the original remains owned by the caller.

This method is the same as the C function GDALSetDefaultRAT().

Parameters
poRATthe RAT to assign to the band.
Returns
CE_None on success or CE_Failure if unsupported or otherwise failing.

Reimplemented from GDALRasterBand.

◆ SetDescription()

void GDALPamRasterBand::SetDescription ( const char *  pszNewDesc)
overridevirtual

Set object description.

The semantics of the description are specific to the derived type. For GDALDatasets it is the dataset name. For GDALRasterBands it is actually a description (if supported) or "".

Normally application code should not set the "description" for GDALDatasets. It is handled internally.

This method is the same as the C function GDALSetDescription().

Reimplemented from GDALMajorObject.

◆ SetMetadata()

CPLErr GDALPamRasterBand::SetMetadata ( char **  papszMetadataIn,
const char *  pszDomain = "" 
)
overridevirtual

Set metadata.

The C function GDALSetMetadata() does the same thing as this method.

Parameters
papszMetadataInthe metadata in name=value string list format to apply.
pszDomainthe domain of interest. Use "" or NULL for the default domain.
Returns
CE_None on success, CE_Failure on failure and CE_Warning if the metadata has been accepted, but is likely not maintained persistently by the underlying object between sessions.

Reimplemented from GDALMajorObject.

◆ SetMetadataItem()

CPLErr GDALPamRasterBand::SetMetadataItem ( const char *  pszName,
const char *  pszValue,
const char *  pszDomain = "" 
)
overridevirtual

Set single metadata item.

The C function GDALSetMetadataItem() does the same thing as this method.

Parameters
pszNamethe key for the metadata item to fetch.
pszValuethe value to assign to the key.
pszDomainthe domain to set within, use NULL for the default domain.
Returns
CE_None on success, or an error code on failure.

Reimplemented from GDALMajorObject.

◆ SetMOFlags()

void GDALMajorObject::SetMOFlags ( int  nNewFlags)
inherited

Assign GMO_flags.

Parameters
nNewFlagsnew flags.

◆ SetNoDataValue()

CPLErr GDALPamRasterBand::SetNoDataValue ( double  dfNoData)
overridevirtual

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 SetNoDataValueAsInt64() or SetNoDataValueAsUInt64() instead.

To clear the nodata value, use DeleteNoDataValue().

This method is the same as the C function GDALSetRasterNoDataValue().

Parameters
dfNoDatathe value to set.
Returns
CE_None on success, or CE_Failure on failure. If unsupported by the driver, CE_Failure is returned by no error message will have been emitted.

Reimplemented from GDALRasterBand.

◆ SetNoDataValueAsInt64()

CPLErr GDALPamRasterBand::SetNoDataValueAsInt64 ( int64_t  nNoDataValue)
overridevirtual

Set the no data value for this band.

This method 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.

To clear the nodata value, use DeleteNoDataValue().

This method is the same as the C function GDALSetRasterNoDataValueAsInt64().

Parameters
nNoDataValuethe value to set.
Returns
CE_None on success, or CE_Failure on failure. If unsupported by the driver, CE_Failure is returned by no error message will have been emitted.
Since
GDAL 3.5

Reimplemented from GDALRasterBand.

◆ SetNoDataValueAsUInt64()

CPLErr GDALPamRasterBand::SetNoDataValueAsUInt64 ( uint64_t  nNoDataValue)
overridevirtual

Set the no data value for this band.

This method 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.

To clear the nodata value, use DeleteNoDataValue().

This method is the same as the C function GDALSetRasterNoDataValueAsUInt64().

Parameters
nNoDataValuethe value to set.
Returns
CE_None on success, or CE_Failure on failure. If unsupported by the driver, CE_Failure is returned by no error message will have been emitted.
Since
GDAL 3.5

Reimplemented from GDALRasterBand.

◆ SetOffset()

CPLErr GDALPamRasterBand::SetOffset ( double  dfNewOffset)
overridevirtual

Set scaling offset.

Very few formats implement this method. When not implemented it will issue a CPLE_NotSupported error and return CE_Failure.

This method is the same as the C function GDALSetRasterOffset().

Parameters
dfNewOffsetthe new offset.
Returns
CE_None or success or CE_Failure on failure.

Reimplemented from GDALRasterBand.

◆ SetScale()

CPLErr GDALPamRasterBand::SetScale ( double  dfNewScale)
overridevirtual

Set scaling ratio.

Very few formats implement this method. When not implemented it will issue a CPLE_NotSupported error and return CE_Failure.

This method is the same as the C function GDALSetRasterScale().

Parameters
dfNewScalethe new scale.
Returns
CE_None or success or CE_Failure on failure.

Reimplemented from GDALRasterBand.

◆ SetStatistics()

CPLErr GDALRasterBand::SetStatistics ( double  dfMin,
double  dfMax,
double  dfMean,
double  dfStdDev 
)
virtualinherited

Set statistics on band.

This method can be used to store min/max/mean/standard deviation statistics on a raster band.

The default implementation stores them as metadata, and will only work on formats that can save arbitrary metadata. This method cannot detect whether metadata will be properly saved and so may return CE_None even if the statistics will never be saved.

This method is the same as the C function GDALSetRasterStatistics().

Parameters
dfMinminimum pixel value.
dfMaxmaximum pixel value.
dfMeanmean (average) of all pixel values.
dfStdDevStandard deviation of all pixel values.
Returns
CE_None on success or CE_Failure on failure.

◆ SetUnitType()

CPLErr GDALPamRasterBand::SetUnitType ( const char *  pszNewValue)
overridevirtual

Set unit type.

Set the unit type for a raster band. Values should be one of "" (the default indicating it is unknown), "m" indicating meters, or "ft" indicating feet, though other nonstandard values are allowed.

This method is the same as the C function GDALSetRasterUnitType().

Parameters
pszNewValuethe new unit type value.
Returns
CE_None on success or CE_Failure if not successful, or unsupported.

Reimplemented from GDALRasterBand.

◆ ToHandle() [1/2]

static GDALMajorObjectH GDALMajorObject::ToHandle ( GDALMajorObject poMajorObject)
inlinestaticinherited

Convert a GDALMajorObject* to a GDALMajorObjectH.

Since
GDAL 2.3

◆ ToHandle() [2/2]

void static GDALRasterBandH GDALRasterBand::ToHandle ( GDALRasterBand poBand)
inlinestaticinherited

Convert a GDALRasterBand* to a GDALRasterBandH.

Since
GDAL 2.3

◆ TryGetLockedBlockRef()

GDALRasterBlock * GDALRasterBand::TryGetLockedBlockRef ( int  nXBlockOff,
int  nYBlockOff 
)
inherited

Try fetching block ref.

This method will returned the requested block (locked) if it is already in the block cache for the layer. If not, nullptr is returned.

If a non-NULL value is returned, then a lock for the block will have been acquired on behalf of the caller. It is absolutely imperative that the caller release this lock (with GDALRasterBlock::DropLock()) or else severe problems may result.

Parameters
nXBlockOffthe horizontal block offset, with zero indicating the left most block, 1 the next block and so forth.
nYBlockOffthe vertical block offset, with zero indicating the top most block, 1 the next block and so forth.
Returns
NULL if block not available, or locked block pointer.

◆ WriteBlock()

CPLErr GDALRasterBand::WriteBlock ( int  nXBlockOff,
int  nYBlockOff,
void *  pImage 
)
inherited

Write a block of image data efficiently.

This method accesses a "natural" block from the raster band without resampling, or data type conversion. For a more generalized, but potentially less efficient access use RasterIO().

This method is the same as the C GDALWriteBlock() function.

See ReadBlock() for an example of block oriented data access.

Parameters
nXBlockOffthe horizontal block offset, with zero indicating the left most block, 1 the next block and so forth.
nYBlockOffthe vertical block offset, with zero indicating the left most block, 1 the next block and so forth.
pImagethe buffer from which the data will be written. The buffer must be large enough to hold GetBlockXSize()*GetBlockYSize() words of type GetRasterDataType(). Note that the content of the buffer might be temporarily modified during the execution of this method (and eventually restored back to its original content), so it is not safe to use a buffer stored in a read-only section of the calling program.
Returns
CE_None on success or CE_Failure on an error.

The documentation for this class was generated from the following files: