[Gdal-dev] Re: Changing colour in tif file

Matt Wilkie matt.wilkie at gov.yk.ca
Thu Nov 9 17:57:53 EST 2006

> I need to replace a value in three bands depending on a condition 
> spanning the three bands, e.g if RGB == 255,0,0 then RGB = 120,60,60 or 
> some such.

If you're lucky enough for the desired data to be a the top or bototm of 
the range you can use the scale command (need to split out the bands 
into separate files first):

	gdal_translate -b 1 rgb-image.tif red.tif
	gdal_translate -scale 0 255 0 254 red.tif ...

where 255 is the value to get rid of. The result unfortunately is not 
the same as converting 255 to nodata.


matt wilkie
Geographic Information,
Information Management and Technology,
Yukon Department of Environment
10 Burns Road * Whitehorse, Yukon * Y1A 4Y9
867-667-8133 Tel * 867-393-7003 Fax

More information about the Gdal-dev mailing list