Retrographic SSensing for the Measurement of Suurface Texture and ShaShaape ape Micah K. Johnson Edward HH. Adelson MIT October 9, 2009noCapturingCapturing geometry geometry • Woodham, 1980 • Zickler, 2002 •• Goldman, 2005 • Hertzmann 2005 Hertzmann, 2005 Immages removed due to copyright restrictions. Seee: 1)) Fig. 10 (baby doll head) in Zickler, T. et al. International Journal of Computer Vision 49, no. 2-3 (2002): 215. (PDF) 2)) Fig. 1 (cast iron teapot) in Goldman, D. B., et al. Proc. Of ICCV 2005. (PDF) 3)) Ceramic cat from Hertzmann, A., and S. Seitz. “Shape and Materials by Example: A Photometric Stereo ApproachStereo Approach.” IEEE PAMI 27 8 (2005)” IEEE PAMI 27, no. 8 (2005).Surface texture and shape Surface texture and shapeCookie Cookie Paint Cl ElClear ElasttomertElastoElastoomers omers •Mt il ldb • Material shhould be clear, soft, durable, etc. • Have tried silicones Have tried silicones and polyurethanes •• Thermoplastic elastomers (TPEs) See accompanying video “ThermoplasticSee accompanying video Thermoplastic elastomers” (lec05_tpe.mov)Bake at 3350 for 30 minutes...Paaint PaaintLights, camLights, cammera, actionmera, action Sensor Ligghts CammeraWhy threWhy threee lights ee lights? shading SFSFFSFSshape • Shape-from-shadinngMultiple lightsMultiple lightss: photometric s: photometric stereo Woodham, 1980 Woodham, 1980RGBRed RGB Red Green BlueCalibrration CalibrrationLookup Table B R G Loo GradientRGB color RGB color Lookupkup Gradient (10,200,3) (0,-0.3) (200,10,3) (0.2, 0.2)S rface rec construction Surface recconstr ctionSee accompanying video ““20 dollar bill” (lec05_20.mov)S nyiing videoSee accompan id “Fingertip” (lec05_finger.mov)S mpanyiing videoSee accom id “Fingertip with lotioon” (lec05_finger2.mov)LimitaLimitaations ations •pends on gel• Limited depth - dep • Some objects distoSome objects distoort when pressed ort when pressed - fingertips, clothRetrographRetrographhic sensinghic sensing • Inexpensive • High-resolution • SimpleSimple • Portable / Interactivve • Acknowledgementss -Funding from NSFunding from NSSF and Adobe SystemsSF and Adobe SystemsMIT OpenCourseWarehttp://ocw.mit.edu MAS.531 Computational Camera and Photography Fall 2009 For information about citing these materials or our Terms of Use, visit: