For anyone interested in this area, the IEEE Transactions on Information Forensics and Security (TIFS) [1] is full of papers on the so-called area of image forensics -- the identification of processing that has been performed upon an image, including resampling, rotation, JPEG compression, block processing, and more.

Consequently, another hot research area is image anti-forensics -- the obfuscation of such operations to avoid detection. (Shameless self-promotion: one example paper on anti-forensics of JPEG compression can be found here [2].)

[1] http://www.signalprocessingsociety.org/publications/periodic...

[2] http://www.mirlab.org/conference_papers/International_Confer...