# How to digitally iron out chewed-up photos



## Engineer Babar (Jul 17, 2009)

A SOPHISTICATED imaging technique used to enhance fossils and ancient engravings may soon help you erase rips and creases from old photographs, using just an ordinary flatbed scanner.

Tom Malzbender of Hewlett-Packard Laboratories in Palo Alto, California, and his colleagues pioneered a method of taking scores of digital photographs of a textured object from slightly different angles to create a computer model of the object's bumps and ridges. The team used it to bring carvings on previously unreadable ancient tablets into sharp relief (New Scientist, 7 April 2001, p 38). But back then the technique involved a metre-wide plastic dome and 50 separate light sources.

Now Malzbender's team has achieved the same effect using an off-the-shelf flatbed scanner. They rely on the fact that modern scanners use two separate light bulbs. This feature was added to scanners to improve colour quality, but it also lets you capture the image from two different angles. Re-scanning the object after rotating it 90 degrees provides a total of four different angles, more than enough to deduce 3D information about the object - mathematically, you only need three.

To fix old, damaged photographs, the software flags every pixel in the scanned image that isn't lying flat against the scanner, an indication that there is a tear or a fold there. Then it automatically replaces those pixels by copying adjacent ones, smoothing over the damaged region (www.hpl.hp.com/techreports/2009/HPL-2009-37.html).

Hewlett-Packard has no immediate plans to release the software commercially, but "anybody with good programming skills could implement this", says Malzbender. "It would take them a while, it's not a slam dunk, but they could do it."

"The premise seems promising," says Bob Kolarik, a professional photograph restorer whose company, Yesteryear Memories, is based in Bolingbrook, Illinois. "If I can reduce the amount of time spent on a restoration project, I would probably go for it."


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## WereBo (Apr 5, 2008)

But but but.... That takes all the fun out of photo-restoration :sigh:


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## Engineer Babar (Jul 17, 2009)

yup werebo may be.. hehehe


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## WereBo (Apr 5, 2008)

Hehehe... Seriously though, I do enjoy restoring old photos, working down at pixel-level - It's a precision job that I really enjoy :grin:.


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## Engineer Babar (Jul 17, 2009)

Thats good. So what you generally thinks about this article? Will this happen in the future? Whats your idea?


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## WereBo (Apr 5, 2008)

I reckon it's very likely, in the near future sometime. 

A lot of photo adjustments that had to worked manually, in the past, can now be done near instantaneously with the various filters that's available - 'Red-eye' reduction, sharpening blurry photos etc. 

All these took time and experimentation a few years ago, but now it's just a couple of clicks and it's done, so it stands to reason that torn and creased photos will get the same treatment eventually - Especially now that PC's are lots more powerful, to work out the various algorithms needed for such repairs.


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