자유곡면의 형상 측정에서 shape-from-shading을 접목한 스테레오 비전의 적용

Abstract

Shape-from-shading (SFS) or stereo vision algorithms can be utilized to measure the shape of an objectwith imaging techniques for effective sensing in non-contact measurements. SFS algorithms could reconstructthe 3D information from a 2D image data, offering relatively comprehensive information. Meanwhile, a stereovision algorithm needs several feature points or lines to extract 3D information from two 2D images. However, to measure the size of an object with a freeform surface, the two algorithms need some additionalinformation, such as boundary conditions and grids, respectively. In this study, a stereo vision scheme usingthe depth information obtained by shape-from-shading as patterns was proposed to measure the size of anobject with a freeform surface. The feasibility of the scheme was proved with an experiment where theimages of an object were acquired by a CCD camera at two positions, then processed by SFS, and finallyby stereo matching. The experimental results revealed that the proposed scheme could recognize the size andshape of freeform surface fairly well.