How to generate polygonal thumbs?

Is there's a way to generate polygonal thumbnails in PHP? (ImageMagick, GD, etc)

Here is an example of what I want to achieve: http://www.area105.com/gallery/shme/thumb开发者_开发技巧1.png

It can be done, and the general process is going to involve using a mask. There was a pretty good write-up by a Stack Overflow user on his blog about making and using a mask. It does not answer your question directly, but should point you in the right direction:

Creating ‘mask layers’ using PHP GD