http://readwrite.com/2011/05/14/4-free-e-books-on-objective-c#awesm=~ovhdJ9RdeJ7Vk3 http://www.cs.colorado.edu/~kena/classes/5448/f11/lectures/12-introtoobjectivec.pdf http://www.cocoalab.com/BecomeAnXcoder.pdf http://pierre.chachatelier.fr/programmation/fichiers/cpp-objc-en.pdf http://it-ebooks.info/go.php?id=1201-1391871296-28241bd5ccd775d0306ee7dd48a737d8 https://developer.apple.com/library/ios/documentation/cocoa/conceptual/ProgrammingWithObjectiveC/ProgrammingWithObjectiveC.pdf

http://andrewd.ces.clemson.edu/courses/cpsc102/notes/ObjC.pdf

https://developer.apple.com/library/ios/documentation/cocoa/conceptual/ProgrammingWithObjectiveC/ProgrammingWithObjectiveC.pdf[^]

I'll suggest use opencv

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