结构光3D扫原理教学课件经典必看

1、Computer VisionSpring 2006 15-385,-685Instructor: S. NarasimhanWean 5403T-R 3:00pm 4:20pmLecture #17Structured Light + Range ImagingLecture #17(Thanks to Slides from Levoy, Rusinkiewicz, Bouguet, Perona)3D ScanningStructured Light ReconstructionAvoid problems due to correspondenceAvoid problems due

2、to surface appearanceMuch more accurateVery popular in industrial settingsReading: Marc Levoys webpages (Stanford)Katsu Ikeuchis webpages (U Tokyo)Peter Allens webpages (Columbia)Stereo TriangulationIJCorrespondence is hard!IJStructured Light TriangulationCorrespondence becomes easier!Structured Lig

3、ht Any spatio-temporal pattern of light projected on a surface (or volume). Cleverly illuminate the scene to extract scene properties (eg., 3D). Avoids problems of 3D estimation in scenes with complex texture/BRDFs. Very popular in vision and successful in industrial applications (parts assembly, in

4、spection, etc).Light Stripe Scanning Single StripeCameraSourceSurfaceLight planeOptical triangulationProject a single stripe of laser lightScan it across the surface of the objectThis is a very precise version of structured light scanningGood for high resolution 3D, but needs many images and takes t

5、imeTriangulationProject laser stripe onto objectObjectLaserCameraLight PlaneCameraTriangulationDepth from ray-plane triangulation:Intersect camera ray with light planeLaserObjectLight PlaneImage PointExample: Laser scannerCyberware face and head scanner+ very accurate 0.01 mm more than 10sec per sca

6、nDigital Michelangelo Project/projects/mich/Example: Laser scannerPortable 3D laser scanner (this one by Minolta)Faster Acquisition?Project multiple stripes simultaneouslyCorrespondence problem: which stripe is which?Common types of patterns: Binary coded light striping Gray/color coded light stripi

7、ngBinary CodingPattern 1Pattern 2Pattern 3Projected over timeExample: 3 binary-encoded patterns which allows the measuring surface to be divided in 8 sub-regions Faster: stripes in images.Binary CodingAssign each stripe a unique illumination codeover time Posdamer 82SpaceTimeBinary CodingPattern 1Pa

8、ttern 2Pattern 3Projected over timeExample: 7 binary patterns proposed by Posdamer & AltschulerCodeword of this pxel: 1010010 identifies the corresponding pattern stripeMore complex patternsZhang et alWorks despite complex appearancesWorks in real-time and on dynamic scenes Need very few images (one

9、 or two). But needs a more complex correspondence algorithmContinuum of Triangulation MethodsSlow, robustFast, fragileMulti-stripeMulti-frameSingle-frameSingle-stripe3D Acquisition from ShadowsBouguet-Perona, ICCV 983D Model Acquisition Pipeline3D Scanner3D Model Acquisition Pipeline3D ScannerView Planning3D Model Acquisition Pipeline3D ScannerAlignmentView Planning3D Model Acquisition Pipeline3D ScannerAlignmentMergingView Planning3D Model Acquisition Pipeline3D ScannerAlignmentMergingDone?View Planning3D Model Acquis