Is there any examples on how to use the rastercalc.py or rastercalcengine.py? And what are the purpose of these python module? Are these modules the same with gdal utilities which can be run in command line? Can I use from any of these two modules in subtracting two raster images?
Usually I use the raster calculator manually, in my case for give more weight to one value in a shp or a raster, also for calculate the IRNV in some raster.
if you want to automatice some task (in the case of the IRNV) you must use the map algebra toolset instead.
Sorry, thats all i know about it [and also sorry for my english :( ]