Dense Light Transport for Relighting Computation Using Orthogonal Illumination Based on Walsh-Hadamard Matrix


IEICE TRANSACTIONS on Information and Systems   Vol.E99-D   No.4   pp.1038-1051
Publication Date: 2016/04/01
Online ISSN: 1745-1361
DOI: 10.1587/transinf.2015CYP0002
Type of Manuscript: Special Section PAPER (Special Section on Cyberworlds)
light transport,  relighting,  color crosstalk,  Walsh-Hadamard matrix,  orthogonal illumination,  

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We propose a practical method that acquires dense light transports from unknown 3D objects by employing orthogonal illumination based on a Walsh-Hadamard matrix for relighting computation. We assume the presence of color crosstalk, which represents color mixing between projector pixels and camera pixels, and then describe the light transport matrix by using sets of the orthogonal illumination and the corresponding camera response. Our method handles not only direct reflection light but also global light radiated from the entire environment. Tests of the proposed method using real images show that orthogonal illumination is an effective way of acquiring accurate light transports from various 3D objects. We demonstrate a relighting test based on acquired light transports and confirm that our method outputs excellent relighting images that compare favorably with the actual images observed by the system.