[gdal-dev] gdalwarp question - probably pretty simple

[David Strip]

On 11/22/2012 10:40 PM, David Strip wrote:
> I've got a geotiff which gdalinfo reports as 2 bands, with band 2 
> interpreted as alpha. The projection is Maryland State Plane. The 
> color table is paletted, with NO_DATA = 0
> I can view this file in OpenEV with no problem
> I call
>     gdalwarp -t "WGS84" input.tif output.tif
> When I open the resulting file in OpenEV, I see nothing, the screen 
> appears to remain black. When I move the cursor around, it reports the 
> value as NO DATA.
>
> I thought this might have something to do with the alpha band, so I 
> added - dstalpha. This produces
>     ERROR 6: SetColorTable() not supported for multi-sample images
> It still completes and produces a file, but gdalinfo doesn't report 
> band2 as alpha, and I still get a blank view in OpenEV.
>
> I suspect I'm missing something quite basic, but I'm not seeing any 
> obvious command option.

I can make this work if I first strip out the alpha band
     gdal_translate -b 1 input.tif output.tif

But I'm still interesting in hearing how I could make gdalwarp work 
directly.