I've found myself evaluating both of these libs. Apart from what the GraphicsMagick comparison says, I see that ImageMagick still got updates and it seems that the two are almost identical.
I'm just looking to do basic image manipulation in C++ (i.e. image load, filters, display); are there any differences I should be aware of when choosing between these libraries?
From what I have read GraphicsMagick is more stable and is faster. I did a couple of unscientific tests and found gm to be twice as fast as im (doing a resize).