sync nice features of r.out.tiff, r.out.png
|Reported by:||hamish||Owned by:|
r.out.tiff has a -t flag to create a world file. r.out.png has a -t flag to make NULL cells transparent.
it would be really useful if they both could have both flags. For use with gdal2tiles.py + OpenLayers you need both but only can get one or the other! Probably it is some pretty easy cutting and pasting of code between the two modules.
GDAL supports extensions of .pgw, .pngw or .wld for PNG World files. http://gdal.org/frmt_various.html#PNG
(& finally, rename the flags in grass7 to make them consistent)
r.out.gdal is no good here because for OpenLayers you care about the colors not the data, and gdal is cranky with color maps.