William, Try gdalwarp after removing the mask band. If that didn't work try gdal_merge.py with -init set to 255.
On Wed, Apr 2, 2014 at 1:44 AM, William Kyngesburye <wokl...@kyngchaos.com>wrote: > 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. > > > ----- > 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 > -- Best regards, Chaitanya kumar CH. +91-9494447584 17.2416N 80.1426E
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