id,summary,reporter,owner,description,type,status,priority,milestone,component,version,severity,resolution,keywords,cc 5692,GetMaskBand() doesn't work on UInt16 RGBA,Even Rouault,Even Rouault,"GDALRasterBand::GetMaskBand() returns ALL_VALID on a UInt16 RGBA dataset because it checks that the alpha band is of type Byte (since according to https://trac.osgeo.org/gdal/wiki/rfc15_nodatabitmask ""The masks are represented as GDT_Byte bands with a value of zero indicating nodata and non-zero values indicating valid data. Normally the value 255 will be used for valid data pixels"") So average overview computation on such a dataset will average everything including the transparent areas whose value is 0",defect,closed,normal,1.11.2,GDAL_Raster,unspecified,normal,fixed,overview uint16 alpha,