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Capturing 3D Surfaces Simply With a Flash Camera

Posted by timothy on from the more-depth-than-I've-got dept.

MojoKid writes with this excerpt from Hot Hardware (linking to a video demonstration): "Creating 3D maps and worlds can be extremely labor intensive and time consuming. Also, the final result might not be all that accurate or realistic. A new technique developed by scientists at The University of Manchester's School of Computer Science and Dolby Canada, however, might make capturing depth and textures for 3D surfaces as simple as shooting two pictures with a digital camera — one with flash and one without. First an image of a surface is captured without flash. The problem is that the different colors of a surface also reflect light differently, making it difficult to determine if the brightness difference is a function of depth or color. By taking a second photo with flash, however, the accurate colors of all visible portions of the surface can be captured. The two captured images essentially become a reflectance map (albedo) and a depth map (height field)."

3 of 131 comments (clear)

  1. Quite old news by gardyloo · · Score: 4, Informative

    Slashdot (can't be bothered to find it) had a story several years ago about the (then old!) technique of capturing complicated 3D objects, such as car engines, by using two flash images, each with the flash located in slightly different locations. Threshholding the difference between the images gives very nice edge detection, along with very accurate depth information.

    A project I'm working on uses the technique to capture information about arrowheads/spearheads.

    1. Re:Quite old news by jellomizer · · Score: 4, Informative

      But this time the camera stays fixed and there is one without flash and the other with it. Allowing for 3D Cameras to be made on the cheap by just a firmware upgrade (one click of the camera takes 2 shots 1 without flash the next with. Your way is different as it requires the camera to have 2 flash thus needed the making of new cameras.

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    2. Re:Quite old news by glyph42 · · Score: 4, Informative

      NOT old news. Google for "2008 siggraph papers". Read the paper. Google for "2004 siggraph papers". Read about the old paper. Note the differences. Tim Rowley posts links to the papers from each year, so his site is recommended. Virtually all of these image-processing-related news items can be read long before they reach slashdot simply by keeping up with the latest papers from siggraph. In case you're lazy, the old paper is "Non-photorealistic Camera: Depth Edge Detection and Stylized Rendering Using a Multi-Flash Camera". Oddly, it's offline now. But I do have a copy of it on my hard drive. If you're not lazy, I HIGHLY recommend perusing all of the years' papers listed on Tim's site.

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