Write Your Own Geospatial Utilities - Open Source Geospatial Tools: Applications in Earth Observation - page 245

//loop over all command line options
for ( int i=1;i<argc;i++){
...
...

}

We then test on the string of the destination image filename ( stlsDestImage -
Filename ). If empty, the input image needs to be updated in the same way as in
the first version. If not empty, the user has provided a filename for the output image
that needs to be created. We will use the GeoTIFF driver for this. A more flexible
solution is provided in our third version.

...
if (stlsDestImageFilename.empty()){//no output provided: update input
//open input dataset in update mode (not supported by all drivers)
poDataset = (GDALDataset *) GDALOpen(

→

stlsSrcImageFilename.c_str(), GA_Update);

//set the color table to the first raster band
poDataset->GetRasterBand(1)->SetColorTable(&oColorTable);

}
else {//create new data set with CreateCopy
//open input dataset in read only mode
GDALDataset *poSrcDataset;
poSrcDataset = (GDALDataset *)
→ GDALOpenShared(stlsSrcImageFilename.c_str(),

→

GA_ReadOnly);

GDALDriver *poDriver;
poDriver = GetGDALDriverManager()->GetDriverByName("GTiff");

//possibility to define some extra create options here...
char **papszOptions = NULL;

//create new data for output
poDataset = poDriver->CreateCopy(stlsDestImageFilename.c_str(),
→ poSrcDataset, FALSE, papszOptions, NULL, NULL);

//set the color table to the first raster band
poDataset->GetRasterBand(1)->SetColorTable(&oColorTable);

//clean up
CSLDestroy(papszOptions);
//close the read only dataset
GDALClose((GDALDataset*) poSrcDataset);

}

//close the dataset
GDALClose((GDALDataset*) poDataset);

The CreateCopy method takes six arguments. The first argument is the file-
name of the dataset to be created ( stlsDestImageFilename ). It is converted
to a C-style string to be compatible with the declaration of the method. The sec-
ond argument defines the source dataset to be copied ( poSrcDataset ). The third
argument is set to FALSE , indicating that the copy must not be strictly equivalent