AW: [gdal-dev] An issue about using GDALWARP todotheNTv2transformation

[Schmitz, Uwe]

Heng,
> 
> Hi Uwe, 
> 
> I have been trying to use gdal_merge.py to merge 
> a few 8 bit colored .tif tiles together. Having 
> tried all sorts of options for this command, I 
> always ended up with a merged 8-bit grayscale picture. 
> I did a search on the internet and found a couple of 
> posts related to this, however it seemed to me that 
> the gdal_merge.py just does not have the ability 
> to preserve the color. Did I get the wrong idea about 
> this? Do you have any suggestion to solve this problem? 
>
you have to specify "-pct" to grab the color table
of the first merged tile for the result file.
And, very important, all input tiles need to have
the *same* color table, because merging is done
on pixel values (that means channels).

> Not sure if I should post a separate message for 
> this gdal_merge.py issue.  I just thought this would 
> be the quickest way to get the help :) 
>
Yes, IMO a seperate post would have been better and
addressing it to me wouldn't always help to get a fast
response ;-)

Regards
Uwe