[gdal-dev] advice on feathering rasters together?

[Matt Wilkie]

Hello,

Does anyone have any advice on how to feather rasters together so there 
is not an abrubt transition from one to the other?

The circumstance: I have 16bit integer raster (a DEM) with some areas in 
it I want to fix (lakes which should be flat). I've created a second 
raster with the desired replacement values (fixed_lakes). However if I 
blindly just substitute fixed_lakes.tif for dem.tif there are some 
pretty abrubt transitions which are sometimes worse than the original 
problem.

I've done this before using Gimp and 8bit images but gimp can't load 
16bit images without losing half the bits. (in layer pallet stack 
fixed.tif over original.tif > transparency to selection for fixed layer 
 > invert selection > expand X pixels > feather > flatten image; restore 
spatial reference with gdalcopyproj.py)

thanks in advance for your thoughts,

-- 
matt wilkie
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