Question: I am researching iPhone image libraries. I am looking for a lightweight image library that will compile on an iPhone. Have any libraries such as ImageMagick been ported? What image libraries would be best suited for the iPhone?

The image library should be suited to do black & white, sepia tone, saturation filters, and more sophisticated effects such as oil painting, etc.

Thank you in advance.

Answer: 
But Core Graphic won't do any of image filtering mention above. That's a part of Core Image, which is apparently missing from iPhone SDK.
I believe there has been some success porting ImageMagick it to iOS:

<http://www.imagemagick.org/discourse-server/viewtopic.php?f=4&t=14089>