[GRASS-user] No color for geotiffs exported with r.out.gdal

[Markus Neteler]

On Fri, Apr 2, 2010 at 5:00 PM, William Hudspeth <bhudspeth at edac.unm.edu> wrote:
> Hello,
>
> I am using GRASS 6.4~rc5-2 on Ubuntu 9.10. I am trying to export a DCELL
> raster map to both a byte formatted and a UInt16 formatted Geotiff file.
> The UInt16 formatted file shows nothing when I try to open the file, and
> the byte formatted file is in black and white only. I can't seem to get
> color. The original GRASS raster uses the "ndvi" color scheme.

NDVI ranges (theoretically) from -1 to +1. Hence not much information
would survive then stored in 0..255 (8 bit) or 0..65535 (16bit UInt).

Solutions are
- select Float32 (but GeoTIFF won't support a color table)
- Add +1 and multiply with 100 and adjust the color table accordingly,
then export to 8bit
- choose a different format which supports color tables in floating
point format,
  check http://www.gdal.org/formats_list.html
- maybe more...

Please post your solution here.

Markus