These look to be a great help, but I have not been able to find a way to use them. The links to the programs that are listed as useable do not exist or do not work. I haven't given up completely but it is very difficult.
[3 of 5 Stars!]
Have you tried to use GIMP? Whcih can be found at www.gimp.org. Gimp is a free graphics editing program which I use in the demo.