Abstract: While historically we may have been overly trusting of photographs, in recent years there has been a backlash of sorts and the authenticity of photographs is now routinely questioned. Because these judgments are often made by eye, we wondered how reliable the human visual system is in detecting discrepancies that might arise from photo tampering. We show that the visual system is remarkably inept at detecting simple geometric inconsistencies in shadows, reflections, and perspective distortions. We also describe computational methods that can be applied to detect the inconsistencies that seem to elude the human visual system.

@inproceedings{farid-bravo-spie-10,
  url          = {http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.156.4908&rep=rep1&type=pdf},
  booktitle    = {SPIE Conference on Media Forensics and Security},
  author       = {Hany Farid and Mary J. Bravo},
  location     = {San Jose, CA},
  year         = {2010},
  title        = {Image forensic analyses that elude the human visual system},
}