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HP Restores Creased Photos With Flatbed Scanners
An anonymous reader writes "Scientists at HP have developed a technique to detect creases in photographs using standard, unmodified flatbed scanners. Once correctly scanned into a computer, software can determine where the photograph's defect is, and artificially correct it to remove any trace of a crease or fold. The result is a spotless JPEG scan from a creased photo, with absolutely no modified hardware and no technical know-how required on the part of the user." They're using multiple light sources to do this, in a way that reminds me of last year's description of 3D image creation using an ordinary digital camera.
Won't this ruin my collection of photographs of creased paper?
Actually, no, it won't. Since the method uses different light sources to build a partial 3D model of the actual shape of the crease, your mere photographic creases won't be detected. You can breathe a sigh of relief.
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Multiple light sources offer some interesting options. A few years ago, someone modified a digital camera (I think a Canon PowerShot) to have four flash sources instead of the usual one. The camera would take four pictures in quick succession, one with each flash. This allowed better edge detection.
It was useful for applications like taking a picture of complex, dirty machinery (as under a car hood) and locating the edges, even where everything was roughly the same shade. It also helped when photographing very shiny objects, where the reflection from the flash was a problem. With each reflection from each flash unit in a different place, all reflections could be removed.
It was too specialized to become mainstream, though. That seems to be the fate of 3D from 2D systems. Good ones have been built, but most have been either discontinued or turned into very expensive products for specialized use.