Picture Window Pro 7 by Digital Light & Color is a capable image editor. For those who might be interested, it is now going out of production after many years, but the final version can be downloaded, key registration is
no longer needed. It can do a great many image and photo editing tasks and some unique ones including creating very complex photo masks and creating unique mathematical patterns and textures. It does however have has its own way of doing things and the interface thus has its own learning curve.
http://www.dl-c.com/ An example pattern I made in Picture Window Pro
