Issue No. 10 - October (2010 vol. 32)
Zhan Song , Chinese Academy of Sciences, ShenZhen
Chi-Kit Ronald Chung , The Chinese University of Hong Kong, Hong Kong
Position and orientation profiles are two principal descriptions of shape in space. We describe how a structured light system, coupled with the illumination of a pseudorandom pattern and a suitable choice of feature points, can allow not only the position but also the orientation of individual surface elements to be determined independently. Unlike traditional designs which use the centroids of the illuminated pattern elements as the feature points, the proposed design uses the grid points between the pattern elements instead. The grid points have the essences that their positions in the image data are inert to the effect of perspective distortion, their individual extractions are not directly dependent on one another, and the grid points possess strong symmetry that can be exploited for their precise localization in the image data. Most importantly, the grid lines of the illuminated pattern that form the grid points can aid in determining surface normals. In this paper, we describe how each of the grid points can be labeled with a unique color code, what symmetry they possess and how the symmetry can be exploited for their precise localization at subpixel accuracy in the image data, and how 3D orientation in addition to 3D position can be determined at each of them. Both the position and orientation profiles can be determined with only a single pattern illumination and a single image capture.
Structured light system, 3D reconstruction, surface orientation, feature detection.
Z. Song and C. R. Chung, "Determining Both Surface Position and Orientation in Structured-Light-Based Sensing," in IEEE Transactions on Pattern Analysis & Machine Intelligence, vol. 32, no. , pp. 1770-1780, 2009.