C++ GDALRasterBand::GetStatistics方法代码示例

/*
     * Initializes the object, assuming that filename, origin, size, etc are already set on the
     * member variables. Makes sure the raster can be opened, sets the block size, NODATA value,
     * pixel size, and the extent of the raster. If not using the full image then makes sure that
     * the subset chosen (based on origin and size) is valid. If using the full image then sets the
     * size and origin is assumed to be 0,0 and is set in the constructor.
     * @param fullImage True if using the full image, False if using a subset.
     */
void Raster::Init(bool bFullImage)
{
    Init();
    GDALDataset * ds = (GDALDataset*) GDALOpen(m_sFilePath, GA_ReadOnly);

    if (ds == NULL)
        throw RasterManagerException(INPUT_FILE_NOT_VALID, CPLGetLastErrorMsg());

    GDALRasterBand * band = ds->GetRasterBand(1);

    double dRMin, dRMax, dRMean, dRStdDev;

    // Get some easy stats that GDAL gives us
    band->GetStatistics( 0 , true, &dRMin, &dRMax, &dRMean, &dRStdDev );
    m_dRasterMax = dRMax;
    m_dRasterMin = dRMin;

    m_dRasterMean = dRMean;
    m_dRasterStdDev = dRStdDev;

    OGRLinearRing ring = OGRLinearRing();
    if (bFullImage)
    {
        SetCols( band->GetXSize() );
        SetRows( band->GetYSize() );

        ring.addPoint(GetLeft(), GetTop());
        ring.addPoint(GetLeft(), GetTop() + (GetCellHeight() * GetRows()));
        ring.addPoint(GetLeft() + (GetCellWidth() * GetCols()), GetTop() + (GetCellHeight() * GetRows()));
        ring.addPoint(GetLeft() + (GetCellWidth() * GetCols()), GetTop());
        ring.closeRings();
    }
    else
    {
        if ((GetLeft() + GetCols() > band->GetXSize()) || (GetTop() + GetRows() > band->GetYSize()))
        {
            QString sErr = QString("Invalid origin ( %1, %2 ) and size ( %5, %6 ) for file: %7")
                    .arg(GetLeft())
                    .arg(GetTop())
                    .arg(GetCols())
                    .arg(GetRows())
                    .arg(FilePath());
            throw RasterManagerException(INPUT_FILE_NOT_VALID, sErr);
        }
        double xMapOrigin = GetLeft() + (GetLeft() * GetCellWidth());
        double yMapOrigin = GetTop() + (GetTop() * GetCellHeight());
        ring.addPoint(xMapOrigin, yMapOrigin);
        ring.addPoint(xMapOrigin, yMapOrigin + (GetCellHeight() * GetRows()));
        ring.addPoint(xMapOrigin + (GetCellWidth() * GetCols()), yMapOrigin + (GetCellHeight() * GetRows()));
        ring.addPoint(xMapOrigin + (GetCellWidth() * GetCols()), yMapOrigin);
        ring.closeRings();
    }
    GDALClose(ds);

}

//.........这里部分代码省略.........

    GDALRasterBand *poSrcBand;
    GDALRasterBand *poDstBand;
    double dfMin;
    double dfMax;
    double dfMean;
    double dfStdDev = -1;

    for( int i = 1; i <= poDstDS->nBands; i++)
    {
        delete poDstDS->GetRasterBand(i);
    }
    poDstDS->nBands = 0;

    if( poDstDS->hHeaderOne.DataTypeCode == Uncompressed24bit )
    {
        poDstDS->SetBand( 1, new IntergraphRGBBand( poDstDS, 1, 0, 3 ) );
        poDstDS->SetBand( 2, new IntergraphRGBBand( poDstDS, 2, 0, 2 ) );
        poDstDS->SetBand( 3, new IntergraphRGBBand( poDstDS, 3, 0, 1 ) );
        poDstDS->nBands = 3;
    }
    else
    {
        for( int i = 1; i <= poSrcDS->GetRasterCount(); i++ )
        {
            poSrcBand = poSrcDS->GetRasterBand(i);
            eType = poSrcDS->GetRasterBand(i)->GetRasterDataType();

            poDstBand = new IntergraphRasterBand( poDstDS, i, 0, eType );
            poDstDS->SetBand( i, poDstBand );

            poDstBand->SetCategoryNames( poSrcBand->GetCategoryNames() );
            poDstBand->SetColorTable( poSrcBand->GetColorTable() );
            poSrcBand->GetStatistics( false, true, &dfMin, &dfMax, &dfMean, &dfStdDev );
            poDstBand->SetStatistics( dfMin, dfMax, dfMean, dfStdDev );
        }
    }

    // --------------------------------------------------------------------
    // Copy image data
    // --------------------------------------------------------------------

    int nXSize = poDstDS->GetRasterXSize();
    int nYSize = poDstDS->GetRasterYSize();

    int nBlockXSize;
    int nBlockYSize;

    CPLErr eErr = CE_None;

    for( int iBand = 1; iBand <= poSrcDS->GetRasterCount(); iBand++ )
    {
        GDALRasterBand *poDstBand = poDstDS->GetRasterBand( iBand );
        GDALRasterBand *poSrcBand = poSrcDS->GetRasterBand( iBand );

        // ------------------------------------------------------------
        // Copy Untiled / Uncompressed
        // ------------------------------------------------------------

        int   iYOffset, iXOffset;
        void *pData;

        poSrcBand->GetBlockSize( &nBlockXSize, &nBlockYSize );

        nBlockXSize = nXSize;
        nBlockYSize = 1;