I have run into a bug using GDALGetMaskFlags() with GTOPO30 data with the GDAL 1.9.0 C API. The test data includes a NoData value:
[dev:~] gdalinfo /cw/testdata/gtopo30/w180s60.dem Driver: EHdr/ESRI .hdr Labelled ... Band 1 Block=7200x1 Type=Int16, ColorInterp=Undefined NoData Value=-9999 When I call GDALGetMaskFlags(), I get back 0x01 which corresponds to GMF_ALL_VALID, meaning that the image is fully opaque. I was hoping to discard the mask band in such a case as an optimization to avoid reading mask samples. However, it appears that the GDALGetMaskFlags() is returing GMF_ALL_VALID by mistake and should be returning GMF_NODATA (0x08) instead. If I use the mask returned from GDALGetMaskBand(), it gives me the proper, variable mask values, so the bug is in falsely reporting the type of the mask band. --------------------------+----------------------+-------------------------- Dr. Craig S. Bruce | Ph 819-771-8303 x205 | CubeWerx Inc. Senior Software Developer | Fax 819-771-8388 | Gatineau, Québec, Canada [email protected] | http://csbruce.com/ | http://www.cubewerx.com/ --------------------------+----------------------+-------------------------- "How many legs does a dog have if you call the tail a leg? Four. Calling a tail a leg doesn't make it a leg." -- Abraham Lincoln _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
