Real-time implementation of a differential range finder
Ramesh M. Rangachar, Tsai Hong Hong, Martin Herman, Jasper C. Lupo · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1990
A scheme is presented for the estimation of differential ranges on the basis of optical flow along a known direction, giving attention to the factors affecting the accuracy of results and various spatial and temporal smoothing algorithms employed to enhance the method's accuracy. It is found that while the use of edge detectors reduces noise, a priori knowledge of the environment improves the method's range discriminability. The method has been implemented on a real-time, high speed pipelined image processing engine capable of processing 60 image frames/sec, using a horizontally moving camera which generates optical flow along a scan line.