Does anyone know of a good starting point to look into pattern and/or photo recognition development for the iPhone? In searching for it, I can only find examples of existing applications, but I would like to start developing one myself.
O'Reilly came out with a book about the OpenCV project recently.
OpenCV is a computer vision library originally developed by Intel. It is free for use under the open source BSD license. The library is cross-platform. It focuses mainly on real-time image processing, as such, if it finds Intel's Integrated Performance Primitives on the system, it will use these commercial optimized routines to accelerate itself.
It is all in C but that should be no problem to call from Objective-C. There are also iPhone port of the OpenCV library available.
If you just wish to see a working application where you do not have to program anything at all but it will give you feedback on how it does its picture recognition try my web-site at: http://www.generalpicturerecognition.com