Image Forensic Analyses that Elude the

Human Visual System

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.