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SUMMARY:Non-Rigid Photometric Stereo with Colored Lights - Gabriel J. Bros
 tow (University of Cambridge)
DTSTART:20080130T140000Z
DTEND:20080130T150000Z
UID:TALK9766@talks.cam.ac.uk
CONTACT:David MacKay
DESCRIPTION:We present an algorithm and the associated capture methodology
  to acquire\nand track the detailed 3D shape\, bends\, and wrinkles of def
 orming\nsurfaces. Moving 3D data has been difficult to obtain by methods t
 hat rely\non known surface features\, structured light\, or silhouettes. M
 ultispectral\nphotometric stereo is an attractive alternative because it c
 an recover a\ndense normal field from an un-textured surface. We show how 
 to capture\nsuch data and register it over time to generate a single defor
 ming\nsurface.\n\nExperiments were performed on video sequences of untextu
 red cloth\, filmed\nunder spatially separated red\, green\, and blue light
  sources. Our first\nfinding is that using zero-depth-silhouettes as the i
 nitial boundary\ncondition already produces rather smoothly varying\nper-f
 rame-reconstructions with high detail. Second\, when these 3D\nreconstruct
 ions are augmented with 2D optical flow\, one can register the\nfirst fram
 e's reconstruction to every subsequent frame.\n
LOCATION:TCM Seminar Room\, Cavendish Laboratory\, Department of Physics
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