[Gdal-dev] Problems when warping II.

[Juan Cicuendez]

Thanks for your help Frank,

Sorry for re-posting this as a new message but I had problems with the
followup option.

I had problems to generate a GeoTiff visible from ERDAS (however is visible
from ENVI) after warping a file, as I mentioned I think it is a problem of
the interleave. Frank suggested to create the GeoTiff with the option
INTERLEAVE=PIXEL, then since I could not find the documentation about the
GeoTiff driver I tested:

char *pszOptions = "INTERLEAVE=PIXEL";

hDstDS = GDALCreate( hDriver, outputfilename, nPixels, nLines, bands, eDT,
&pszOptions );

but it does not work. How can I set this option?, is the documentation of
the GeoTiff driver available anywhere?

Thanks a lot,
Juan

I also put up the code:

CPLErr change_projection(char *filename, char *outputfilename, char
*pszDstWKT)
{

    GDALDriverH hDriver;
    GDALDataType eDT;
    GDALDatasetH hDstDS;
    GDALDatasetH hSrcDS;

    // Open the source file.
    hSrcDS = GDALOpen( filename, GA_ReadOnly );
    CPLAssert( hSrcDS != NULL );

    // Create output with same datatype as first input band.

    eDT = GDALGetRasterDataType(GDALGetRasterBand(hSrcDS,1));

    // Get output driver (GeoTIFF format)

    hDriver = GDALGetDriverByName( "GTiff" );
    CPLAssert( hDriver != NULL );

    // Get Source coordinate system.

    char *pszSrcWKT = NULL;

    pszSrcWKT = (char *) GDALGetProjectionRef( hSrcDS );
    CPLAssert( pszSrcWKT != NULL && strlen(pszSrcWKT) > 0 );


    // Create a transformer that maps from source pixel/line coordinates
    // to destination georeferenced coordinates (not destination
    // pixel line).  We do that by omitting the destination dataset
    // handle (setting it to NULL).

    void *hTransformArg;

    hTransformArg =
        GDALCreateGenImgProjTransformer( hSrcDS, pszSrcWKT, NULL, pszDstWKT,
FALSE, 0.0, 1 );
    CPLAssert( hTransformArg != NULL );

    // Get approximate output georeferenced bounds and resolution for file.

    double adfDstGeoTransform[6];
    int nPixels=0, nLines=0;
    CPLErr eErr;

    eErr = GDALSuggestedWarpOutput( hSrcDS, GDALGenImgProjTransform,
hTransformArg,
                                                adfDstGeoTransform,
&nPixels, &nLines );
    CPLAssert( eErr == CE_None );

    // Create the output file.
    int bands = GDALGetRasterCount(hSrcDS);
    char *pszOptions = "INTERLEAVE=PIXEL";

    hDstDS = GDALCreate( hDriver, outputfilename, nPixels, nLines, bands,
eDT, &pszOptions );

    CPLAssert( hDstDS != NULL );

    // Write out the projection definition.

    GDALSetProjection( hDstDS, pszDstWKT );
    GDALSetGeoTransform( hDstDS, adfDstGeoTransform );

    // Copy the color table, if required.

    GDALColorTableH hCT;

    hCT = GDALGetRasterColorTable( GDALGetRasterBand(hSrcDS,1) );
    if( hCT != NULL )
        GDALSetRasterColorTable( GDALGetRasterBand(hDstDS,1), hCT );

    GDALClose( hDstDS );

    hDstDS = (GDALDataset *) GDALOpen( outputfilename, GA_Update );


    // Setup warp options.

    GDALWarpOptions *psWarpOptions = GDALCreateWarpOptions();

    psWarpOptions->hSrcDS = hSrcDS;
    psWarpOptions->hDstDS = hDstDS;

    psWarpOptions->nBandCount = 0;

    psWarpOptions->pfnProgress = GDALTermProgress;

    // Establish reprojection transformer.

    psWarpOptions->pTransformerArg =
        GDALCreateGenImgProjTransformer( hSrcDS,
                                         pszSrcWKT,
                                         hDstDS,
                                         pszDstWKT,
                                         FALSE, 0.0, 1 );

    psWarpOptions->pfnTransformer = GDALGenImgProjTransform;

    // Initialize and execute the warp operation.

    GDALWarpOperation oOperation;

    oOperation.Initialize( psWarpOptions );
    oOperation.ChunkAndWarpImage( 0, 0,
                                  GDALGetRasterXSize( hDstDS ),
                                  GDALGetRasterYSize( hDstDS ) );


    GDALDestroyGenImgProjTransformer( psWarpOptions->pTransformerArg );
    GDALDestroyWarpOptions( psWarpOptions );


    GDALClose( hDstDS );
    GDALClose( hSrcDS );


    return eErr;
}