Dartmouth College computer scientist Hany Farid says the iconic photograph of Lee Harvey Oswald holding a rifle and Marxist newspapers is not a fake and was almost certainly not altered. Oswald and others claimed the photograph was a forgery due to seemingly inconsistent lighting and shadows. Farid and his team have developed digital forensic tools to determine if digital photos have been manipulated. The tools can measure statistical inconsistencies in the underlying image pixels, improbable lighting and shadow, physically impossible perspective distortion, and other changes made by photo manipulation. “The human brain, while remarkable in many aspects, also has its weaknesses,” Farid says. “The visual system can be quite inept at making judgments regarding 3D geometry, lighting, and shadows.” The lighting and shadows in the Oswald photo appear to be incongruous with outdoor lighting. To test this possibility, Farid created a three-dimensional model of Oswald’s head and portions of the backyard scene, which he used 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,” Farid says. “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.”
For More Information Visit: http://www.cpccci.com
This entry was posted on Saturday, November 7th, 2009 at 1:29 am and is filed under Computer Science and Engineering News. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.