I'm developing a steganography app where the user can hide a "secret message" within an image. One way to do that is by manipulating the DCT coefficients of jpeg images which can be done using the LibJPEG (http://www.ijg.org/) library. I now that I access the DCT coefficients in libjpeg using the jpeg_read_coefficients function. My problem is that I don't know how to compile/use LibJPEG within my xCode project. I read that I need to compile LibJPEG for two architectures: ARM, for iOS, and x86, for the simulator but I don't know how to do that. I have tried a few different approaches, but being a bit naive, nothing seems to work! Can anyone link me to a tutorial or give me a push in the right direction? If anyone successfully installed and used jpeg library please help.. I'm working on Mountain Lion OS X 10.8 and using xCode v4.5.