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All images are compressed. The images in this file is not the original ones. Photometric stereo using graph cut and M-estimation for a virtual tumulus in the presence of highlights and shadows. Daisuke Miyazaki The University of Tokyo Previously Hiroshima City University Currently
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All images are compressed. The images in this file is not the original ones. Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Photometric stereo using graph cut and M-estimation for a virtual tumulus in the presence of highlights and shadows Daisuke Miyazaki The University of Tokyo Previously Hiroshima City University Currently Katsushi Ikeuchi The University of Tokyo Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Virtual Tumulus [Laser range sensor] [Photometric stereo] Overall geometry Fine details Virtual Tumulus Project Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Proposed method • Photometric stereo • Graph cut • Robust to outliers: shadow, specular reflection • Point light source in far distance with small size: directional light • Typically around 5 to 8 number of light sources • The direction (and the power) of light sources are known Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Candidates of surface normal Photometric Stereo using 3 intensities [Example] Choose 3 intensities from 5 inputs Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Candidates selection Neighboring surface normal: smooth Image 0 0 Contaminated pixel with specular/shadow Diffuse-only pixel 1 1 Choose Candidates Smooth surface normal Graph cut Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Cost function Data cost Smoothness cost Sum of all pixels Constant weight Sum of all pixels Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Data cost of pixel p M-estimation (Lorentz function) Surface normal Image brightness Light source direction Shading (Lambert's law) (Cosine function) Robust to outlier (shadow, specular reflection, noise) Albedo (Diffuse reflectance) including light source color and brightness Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Smoothness cost of neighboring pixels p & q Albedo Surface normal Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Graph structure sink sink p q p source source Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Algorithm overview KC3 candidates (surface normal & albedo) Initial value Graph cut (Estimate surface normal) [albedo fixed] Graph cut (Estimate albedo) [surface normal fixed] Iterate 3-4 Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Example of input images Specular object Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Result Median-PS: Miyazaki et al. IJCV 2010 GC-PS: Proposed method Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Evaluation Shadowcut PS Conventional PS Wu's PS Median PS Proposed method Input 20.69 (149%) 41.61 (300%) 11.13 (80%) 13.76 (99%) 13.85 (100%) Surface normal (error) Polarization stereo using graph cut (Miyazaki, Ikeuchi)
The University Museum, The University of Tokyo Chlamys australis (Australian scallop) Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Museum Result Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Segonko Tumulus • Relief colored by red, green, yellow paints • Not open to the public • ~A.D.500 Kumamoto Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Scanning Mission 2007 Aug 1st: preparation 2007 Aug 2nd: scanning (typhoon) 2007 Aug 3rd: data processing 2007 Aug 4th: scanning (hot) 2007 Aug 5th: data processing 2007 Aug 6th: scanning (sudden shower) 2007 Aug 7th: finishing Polarization stereo using graph cut (Miyazaki, Ikeuchi)
8-Light Measurement System Photometric Wing Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Scanning Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Images Input image Rendered image Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Segonko result Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Sakurakyo Tumulus Keyhole-shaped tumulus 41m End of 6th century Carved triangle Painted with red, green, yellow Closed Mission: 2010 Jan Fukuoka Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Conclusion Graph Cut Photometric Stereo Virtual Museum Segonko Tumulus Sakurakyo Tumulus 3D Digital Archiving Polarization stereo using graph cut (Miyazaki, Ikeuchi)
Future Work Hiroshima A-bombed materials Shadow & specular Faded texture Discontinuity Polarization stereo using graph cut (Miyazaki, Ikeuchi)
(c) Daisuke Miyazaki 2010All rights reserved. http://www.cg.info.hiroshima-cu.ac.jp/~miyazaki/ Daisuke Miyazaki, Katsushi Ikeuchi, "Photometric stereo using graph cut and M-estimation for a virtual tumulus in the presence of highlights and shadows," Proceedings of Workshop on Application of Computer Vision to Archaeology, San Francisco, CA USA, June 2010 Polarization stereo using graph cut (Miyazaki, Ikeuchi)