How to make an app similar to Fat Booth for the iPhone

I'm just c开发者_运维问答urious how they make apps like Fat Booth for the iPhone? I've been learning/developing iphone apps for the last couple of months but have never ventured into anything image/photo/game based, how on earth do you do image manipulation within objective c? Is it with similar libraries to Cocos 2D or something?

cocos2d is for game animations. what you want is image processing.

entering something along the lines of "objective-c image processing" into google is a good place to start. projects like http://code.google.com/p/simple-iphone-image-processing/ will give you an idea of how you manipulate image data in objective-c. And you never know, there may be an open source library that does the kind of morphing you're looking for.

I just released an app on the app store that internally had to implement a rudimentary version of FatBooth in order to achieve the final effect. Take a look at Displacement Mapping for an idea as to how you can get images to bend, expand, shrink, bloat, etc. FatBooth might have approached it a different way, but this is certainly one approach that would have worked just fine for FatBooth.