Detect fake photos through incompatible shadows

A group of researchers from the University of California at Berkeley and Dartmouth College have developed geometric techniques to identify physically incompatible shadows in the photograph. The program they created allows you to project a light source for each shadow and detect a discrepancy.


^{Photo by NASA, 1969. The place of the common light source is circled in black.}

The program does not work fully automatically. The operator will still have to manually create guides, connecting the points of the shadow and the corresponding and points on the object that casts a shadow. This process is shown in more detail in demo videos: 1 , 2 , and step by step through the illustrations.


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Scientific work with a description of the new technology was published at the conference SIGGRAPH 2013.

On video: recording a presentation at SIGGRAPH 2013.


One of the authors of the scientific work admitted that such a tool can be used not only to verify the authenticity of photographs, but also to make better fakes. In his opinion, a lot of programs are required that check photos according to different criteria, and then the task of the dishonest “artist” will become much more complicated.