Le mardi 01 avril 2014 22:14:11, William Kyngesburye a écrit : > I've wrestled with various nodata issues in the past, now it's hitting me > again... > > I'm using Photoshop to delete collars on scanned maps, creating an alpha > mask. GDAL has no problem with this. What I want to do is merge maps > together (after rectification), then set any remaining nodata areas to > white, RGB 255,255,255. Just dropping the extra alpha band doesn't work > because nodata is set to 0,0,0, which is black. The a_nodata option in > gdal_translate just defines what existing value in the data is nodata. > > I tried using gdalwarp with the -dstnodata option which should set nodata > values in the output to a specific value, but it carries along the alpha > band and ignores dstnodata. > > gdalwarp -dstnodata "255 255 255" in.tif out.tif > Processing input file in.tif. > Using band 4 of source image as alpha. > Using band 4 of destination image as alpha.
You can perhaps try adding -wo INIT_DEST="255,255,255,0" > > > ----- > William Kyngesburye <kyngchaos*at*kyngchaos*dot*com> > http://www.kyngchaos.com/ > > First Pogril: Why is life like sticking your head in a bucket filled with > hyena offal? Second Pogril: I don't know. Why IS life like sticking your > head in a bucket filled with hyena offal? First Pogril: I don't know > either. Wretched, isn't it? > -HitchHiker's Guide to the Galaxy > > > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/gdal-dev -- Geospatial professional services http://even.rouault.free.fr/services.html _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev