Single lens stereo with a biprism

Abstract

We present a novel and practical stereo vision system that uses only one camera and a biprism placed in front of the camera. The equivalent of a stereo pair of images are formed as the left and right halves of a single CCD image by using a biprism placed in front of the lens of a CCD camera. The system is therefore cheap and extremely easy to calibrate since it requires only one CCD camera. An additional advantage of the geometrical set-up is that corresponding features automatically lie on the same scan line. There is also no need for the normalization of image intensities (needed for correlation matching); the calibration of intrinsic parameters of two cameras; nor rectification. A prototype system has been built and tested. The single camera and biprism have led to a simple stereo system for which correspondence is very easy and which is accurate for nearby objects in a small field of view. Preliminary results are presented. Results are extremely promising in the area of cheap sensors for many robotic applications. 1.