Differential Stereo Vision Systems with Dynamical 3-D Reconstruction Scheme
Shigeru Ando, Toshiyuki TABEI · Transactions of the Society of Instrument and Control Engineers · 1988
The purpose of this paper is to solve a narrow depthrange problem of the differential stereo vision systems which has been regarded as an essential drawback of the principle. It is enabled by extracting a reliable depth slice from series of measurements and by accumulating them dynamically while changing a convergence angle of the stereo cameras. For this purpose, three self-evaluators for 1) feasibility, 2) consistency, and 3) error variance of measurements are defined by statistical consideration of the estimators. By combining these quantities, we separate reliable depth regions from ineffective ones of excessive depth. Then, these slices are accumulated to build up a total 3-D shape. The accumulation algorithm is nearly optimum because it is derived from least square criteria based on the evaluated statistics. Estimating inter-slice shifts internally, it can work even if the absolute depth of the slices are unavailable. According to the several experiments, we found the proposed method was added great performance owing to absolute accuracy improvement by implicit averaging effects and to relative accuracy improvement by the range expansion.