Abstract: With increasing technical advances, computer graphics are becomingmore photorealistic. Therefore, it is important to develop methods for distinguishing between actual photographs from digital cameras and computer generated images. We describe a novel approach to this problem. Rather than focusing on the statistical differences between the image textures, we recognize that images from digital cameras contain traces of resampling as a result of using a color filter array with demosaicing algorithms. We recognize that estimation of the actual demosaicing parameters is not necessary; rather, detection of the presence of demosaicing is the key. The in-camera processing (rather than the image content) distinguishes the digital camera photographs from computer graphics. Our results show high reliability on a standard test set of JPEG compressed images from consumer digital cameras. Further, we show the application of these ideas for accurately localizing forged regions within digital camera images.

  url          = {http://amp.ece.cmu.edu/people/Andy/Andy_files/CVPR08WVUGallagher.pdf},
  booktitle    = {Proc. CVPR WVU Workshop},
  author       = {Andrew C. Gallagher and Tsuhan Chen},
  year         = {2008},
  title        = {Image authentication by detecting traces of demosaicing},