PNG 24bit driver installation (PNG driver upgrade from 8bit to 24bit): 1. start grass5 2. cd $GISBASE 3. mv driver/PNG driver/PNG.8bit 4. tar xvfz pngdriver24_i686-pc-linux-gnu.tar.gz Note that this driver requires GD library >= V2.0 (http://www.boutell.com/gd/)