Nagesh wrote: > I intend to mosaic two 24 bit images in LAT LON location. > I imported a 24 bit coloured PNG image in Grass using > r.in.gdal in an x-y location. > GRASS treated it as a combination of three 8 bit images, > one for red, one for green, and one for blue and imported > them as three separate maps. > > After going through the archives, I tried to use r.patch to > combine all the three components.
I think you mean to use r.composite there, not r.patch. > The output of which wasn't a 24bit image but was only > one of the components. (Not coloured) the first map was "patched" over top of the other two. > d.rgb module does display a coloured 24 bit image after > inputing the three components to it. Correct. > I geocoded them to get non-coloured 8 bit geocoded images > in the target location. > > I did the same for the second 24 bit image. > Mosaicing works fine(i.image.mosaic), but i need to use 8 > bit images(24 bit images converted to 8 bit images prior to > importing, using xv; resolution weak) > or any one of the 8 bit components of a 24 bit image. > > Is there a way to mosaic 24 bit images and to output it as > a single 24 bit image? # expand region to cover both image regions g.region rast=map1.red,map2.red # merge bands together for COLOR in red green blue ; do r.patch in=map1.${COLOR},map2.${COLOR} out=map.${COLOR} end # display mosaicked image d.rgb r=map.red g=map.green b=map.blue You will lose information if you use r.composite, best to keep bands separate unless you absolutely must combine them. (e.g. for NVIZ color drape) Hamish _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user