ossimGdalDatasetRasterBand Class Reference

ossimGdalDatasetRasterBand Represents a single band within the image. More...

#include <ossimGdalDataset.h>

Inheritance diagram for ossimGdalDatasetRasterBand:

Public Member Functions
	ossimGdalDatasetRasterBand (ossimGdalDataset *ds, int band, ossimImageHandler *ih)
	Constructor that takes a ossimGdalDataset, band and image handler. More...
virtual	~ossimGdalDatasetRasterBand ()
	virtual destructor More...
virtual double	GetNoDataValue (int *pbSuccess=0)
	This returns 0 right now and should probably be implemented if anything serious is to be done with this data set with the gdal library. More...

Protected Member Functions
virtual CPLErr	IReadBlock (int nBlockXOff, int nBlockYOff, void *pImage)
	Read block method. More...

Private Attributes
ossimRefPtr< ossimImageHandler >	theImageHandler

Friends
class	ossimGdalDataset

Detailed Description

ossimGdalDatasetRasterBand Represents a single band within the image.

Definition at line 92 of file ossimGdalDataset.h.

Constructor & Destructor Documentation

ossimGdalDatasetRasterBand()

ossimGdalDatasetRasterBand::ossimGdalDatasetRasterBand	(	ossimGdalDataset *	ds,
		int	band,
		ossimImageHandler *	ih
	)

Constructor that takes a ossimGdalDataset, band and image handler.

Parameters

ds	The parent data set.
band	The "ONE" based band.
ih	The pointer to the image handler.

Definition at line 184 of file ossimGdalDataset.cpp.

   : GDALPamRasterBand(),
     theImageHandler(ih)

{
   if (traceDebug())
   {
      ossimNotify(ossimNotifyLevel_DEBUG)
         << "ossimGdalDatasetRasterBand::ossimGdalDatasetRasterBand entered..."
         << "band: " << band
         << std::endl;
   }
   if (!ih)
   {
      return;
   }
   
   poDS     = ds;
   nBand    = band;

   nRasterXSize     = theImageHandler->getImageRectangle(0).width();
   nRasterYSize     = theImageHandler->getImageRectangle(0).height();
   
   // eAccess  = GA_ReadOnly;
   eAccess  = GA_Update;
   
   ossimGdalType gt;
   eDataType = gt.toGdal(theImageHandler->getOutputScalarType());
   
   nBlockXSize      = theImageHandler->getTileWidth();
   nBlockYSize      = theImageHandler->getTileHeight();

    // ESH 06/2009: Prevent divide by zero.
   nBlockXSize      = (nBlockXSize==0) ? 1 : nBlockXSize;
   nBlockYSize      = (nBlockYSize==0) ? 1 : nBlockYSize;
   
   nBlocksPerRow    = nRasterXSize / nBlockXSize;
   nBlocksPerColumn = nRasterYSize / nBlockYSize;
   if (nRasterXSize % nBlockXSize) ++nBlocksPerRow;
   if (nRasterYSize % nBlockYSize) ++nBlocksPerColumn;

   nBlockReads = 0;
   bForceCachedIO = false;
}

~ossimGdalDatasetRasterBand()

ossimGdalDatasetRasterBand::~ossimGdalDatasetRasterBand ( )

virtual

virtual destructor

Definition at line 231 of file ossimGdalDataset.cpp.

{
}

Member Function Documentation

GetNoDataValue()

double ossimGdalDatasetRasterBand::GetNoDataValue ( int *  pbSuccess = 0 )

virtual

This returns 0 right now and should probably be implemented if anything serious is to be done with this data set with the gdal library.

Definition at line 268 of file ossimGdalDataset.cpp.

{
   if (traceDebug())
   {
      ossimNotify(ossimNotifyLevel_DEBUG)
         << "ossimGdalDatasetRasterBand::GetNoDataValue entered..."
         << "\n"
         << std::endl;
   }

   return 0.0;
}

IReadBlock()

CPLErr ossimGdalDatasetRasterBand::IReadBlock ( int  nBlockXOff, int  nBlockYOff, void *  pImage  )

protectedvirtual

Read block method.

Parameters

nBlockXOff	X Block offset, "0" being upper left sample of image, 1 being sample at nBlockXOff * nBlockXSize and so on.
nBlockYOff	YBlock offset, "0" being upper left sample of image, 1 being sample at nBlockYOff * nBlockYSize and so on.
pImage	Buffer to put image data in. Must be at least: pixel_size_in_bytes * nBlockXSize * nBlockYSize

Returns

CE_None on success, CE_Failure on failure.

Definition at line 235 of file ossimGdalDataset.cpp.

References ossimDataObject::getDataObjectStatus(), ossimImageSource::getTile(), OSSIM_FULL, OSSIM_PARTIAL, theImageHandler, ossimImageData::unloadBand(), ossimRefPtr< T >::valid(), ossimIpt::x, and ossimIpt::y.

{
   if ( !theImageHandler.valid() || !pImage)
   {
      return CE_Failure;
   }

   ossimIpt startPt(nBlockXOff*nBlockXSize, nBlockYOff*nBlockYSize);
//    ossimIpt endPt( min(startPt.x+nBlockXSize-1, nRasterXSize-1),
//                    min(startPt.y+nBlockYSize-1, nRasterYSize-1));
   ossimIpt endPt( startPt.x+nBlockXSize-1,
                   startPt.y+nBlockYSize-1);
   ossimIrect rect( startPt, endPt);

   ossimRefPtr<ossimImageData> id = theImageHandler->getTile(rect, 0);
   
   if (id.valid())
   {
      if( (id->getDataObjectStatus() == OSSIM_FULL) ||
          (id->getDataObjectStatus() == OSSIM_PARTIAL) )
      {
         id->unloadBand(pImage, rect, nBand-1);
         return CE_None;
      }
   }

   memset(pImage, 0, nBlockXSize * nBlockYSize);      

   return CE_None;
}

Friends And Related Function Documentation

ossimGdalDataset

friend class ossimGdalDataset

friend

Definition at line 94 of file ossimGdalDataset.h.

Member Data Documentation

theImageHandler

ossimRefPtr<ossimImageHandler> ossimGdalDatasetRasterBand::theImageHandler

private

Definition at line 138 of file ossimGdalDataset.h.

Referenced by IReadBlock().

---

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

• ossimGdalDataset.h
• ossimGdalDataset.cpp