[GRASSLIST:1433] Re: r.patch geotiff-mosaic wrong color problem

[Richard Greenwood]

At 11:08 PM 10/7/2003 +0200, you wrote:
>Hello Mr. Greenwood,
>
>It worked!!! I did exactly as you told, but I used Corel instead of Gimp.
>i saved the geotiff header of each original 24bit-image to textfiles. Then I
>just loaded one tiff, created an optimized 8bit-color palette and saved this
>palette. Now I just had to reduce each tiff from 24 to 8bit using exactly
>this palette.
>Now write back the geotiff header to each image, cause it's lost after saving
>with corel. Then import all geotiff with r.in.gdal.
>I checked the color palette files in the .../colr directory to be sure  - and
>yes they had all the same values.

I'm glad it worked. You can save a step with gdal_translate - it will write 
out a world file (.tfw) before you convert it with Photoshop or Gimp. Then 
when you r.in.gdal that .tfw file will be read and used to georeference the 
image.

>(I need to invest some time in Gimp, I think reducing images with predefined
>color palette can be done with it too.)

Yes, the steps are very similar to Photoshop (even the menus are similar).

Best regards,
Rich



Richard W. Greenwood, PLS
Greenwood Mapping, Inc.
Rich <at> GreenwoodMap <dot> com
(307) 733-0203
http://www.GreenwoodMap.com