[GRASS-dev] new r.out.gdal fails to preserve 8bit color

[Markus Neteler]

Moritz Lennert wrote on 01/17/2007 09:23 AM:
> On 16/01/07 22:14, Markus Neteler wrote:
>> On Tue, Jan 16, 2007 at 09:53:41PM +0100, Markus Neteler wrote:
>>> On Tue, Jan 16, 2007 at 07:03:15PM +0100, Maciej Sieczka wrote:
>>>> Maciej Sieczka wrote:
>>>>> Vytautas,
>>>>>
>>>>> Exporting a CELL GRASS raster, value range 0-255, r.out.gdal 
>>>>> issues an:
>>>>>
>>>>> ERROR 6: SetColorInterpretation() not supported for this dataset.
>>>>>
>>>>> and the output map is greyscale.
>>>> There is a discussion about this defect on the GDAL dev list:
>>>> http://www.nabble.com/r.out.gdal%3A-SetColorInterpretation%28%29-not-supported-tf3021127.html 
>>>>
>>>>
>>> Probably the mapgdal.c file of MapServer could be an inspiration?
>>
>> I found some more:
>>
>> http://www.nabble.com/Re:-How-to-set-a-ColorTable-from-scratch--p5000321.html 
>>
>> http://www.archivesat.com/FreeGIS_project/thread1933209.htm
>>
>> and GDAL
>> apps/gdalwarpsimple.c
>>
>> Still lost :-)
>
>
> In the very first thread, Frank says:
>
> "Generally speaking to produce a GeoTIFF file with a color table after 
> using Create() to create it, you need to do the SetColorTable() 
> *before* writing any raster data."
>
> I don't see any call to SetColorTable in main.c of r.out.gdal. Could 
> this be the problem ?

Yes.
Right now I have submitted related code based on the GRASS-GDAL plugin.
It now creates color rules, but the color interpretation is still wrong 
(gray instead of RGB).

Please someone may revisit it.

Markus