Easy wallpaper slicing for N900

First, create a 3200x480 png file (For 4 desktops), and using ImageMagick slice it up:

convert wp.png -quiet -crop 800x wp_%d.png

Or you can use this template makefile when your working on your wallpaper:

BASEIMAGE=wp

all: $(BASEIMAGE)_0.png

$(BASEIMAGE)_0.png: $(BASEIMAGE).png
 convert $(BASEIMAGE).png -quiet -crop 800x  $(BASEIMAGE)_%d.png