The python imaging library is pretty good for this kind of thing.
http://www.pythonware.com/library/pil/handbook/
Here's an (untested) example. Hope it helps.
Jake
#!/usr/bin/env python
from pylab import scatter, save
import Image
#get the background image, and find out how big it is
Hanno,
I wrestled with this one for a while. The attached script is the result
of my effort. The two keys were to define the colormap, and then make
sure that when you call the colormap that the values span the full
range. For example, if you want a data point to be "yellow", and that
color (RGB: 1
