[GRASS-user] color not getting imported for raster format

[Glynn Clements]

Nitin wrote:

> i am currently having grass6.1beta version installed with gdal1.3.1.
> 
> While doing import for a jpeg or png file to GTiff format, colours
> do not get imported. It do make differen files for blue, red green
> but ..
> 
> any thing i am miising?

Either generate a composite map from the separate bands using
r.composite, or (preferably) process and display the bands separately.

To display the map, use d.rgb instead of d.rast. For printing, use
ps.map's "rgb" command instead of the "raster" command. For export,
use r.out.ppm3.

Generating a composite map will normally result in loss of colour
resolution. By default, r.composite uses 32 intensity levels per band,
resulting in 32,768 colours (15-bpp). Using 256 levels per band
results in huge colour tables, which tends to result in significantly
increased CPU and memory usage when processing the map.

Also, the display functions used by d.rast will resample images to a
maximum of 32,768 colours, while d.rgb doesn't have this limitation.

-- 
Glynn Clements <glynn at gclements.plus.com>