Washington, Nov 6 A Dartmouth computer scientist insists that the iconic photograph of accused John F. Kennedy assassin Lee Harvey Oswald, showing him holding a rifle in one hand and Marxist newspapers in the other, is not fake.
While Oswald and others claimed that the incriminating photo was a fake, noting the seemingly inconsistent lighting and shadows, Hany Farid claims that the photograph is certainly not altered.
"If we had found evidence of photo tampering, then it would have suggested a broader plot to kill JFK," said Farid, who is also the director of the Neukom Institute for Computational Science at Dartmouth.
"Those who believe that there was a broader conspiracy can no longer point to this photo as possible evidence," he added.
He said federal officials long ago said that this image had not been tampered with, but a surprising number of skeptics still assert that there was a conspiracy.
Farid analysed the photograph with help of digital forensic tools that can measure statistical inconsistencies in the underlying image pixels, improbable lighting and shadow, physically impossible perspective distortion, and other artifacts introduced by photo manipulators.
"The human brain, while remarkable in many aspects, also has its weaknesses. The visual system can be quite inept at making judgments regarding 3-D geometry, lighting, and shadows," said Farid.
At a casual glance, the lighting and shadows in the Oswald photo appear to many to be incongruous with the outdoor lighting. To determine if this was the case, Farid constructed a 3-D model of Oswald's head and portions of the backyard scene, from which he was able to determine that a single light source, the sun, could explain all of the shadows in the photo.
"It is highly improbable that anyone could have created such a perfect forgery with the technology available in 1963," said Farid.
With no evidence of tampering, he concluded that the incriminating photo was authentic.
"As our digital forensic tools become more sophisticated, we increasingly have the ability to apply them to historic photos in an attempt to resolve some long-standing mysteries," he added.
The report appears in journal Perception. (ANI)
