[GRASSLIST:687] patching together aerial photographs

[Jeroen Wortel]

Hi all,

I have a series of georeferenced aerial photographs as 8 bit tiff files.
I have imported these into Grass using r.in.gdal and can visualize 
them with d.rast
Now I want to patch them together in order to use them in NVIZ as color raster.

Because the images are 8 bit indexed colours I can't use r.patch to 
patch the images together in one go.
I suppose I have to split the images first into red, green and blue 
bands, patch each band together with r.patch, and combine the patched 
red, green and blue bands again.

I can't find the Grass command to split the raster image in to red, 
green and blue rasters. How do I do this in Grass? Is there another 
way of achieving a patched image of the aerial photographs?

Any help is greatly appreciated,

thanks,

-Jeroen.