Continuous principal distance change for binocular depth perception

摘要

Depth information can be computed from two cameras arranged in a stereo fashion by using continuous changes of the distance between the lens plane and the image plane (principal distance). This method has the advantage of computing over time the relative depth map with respect to an initial fixation point in space. Using continuous change on the principal distance, the effect of scaling with the object distance on the ‘cyclopean’ (binocular-fused) image and relative depth map is simultaneously compensated for parts of the object lying about the initial fixation point. The ‘appearance’ of the relative depth map and the binocular fused image acquired during the movements, correspond to an orthographic projection of the object and not the perspective projection of it. As a consequence, parallel lines or parallel borders on the object remain parallel on the binocular fused image and on the relative depth for any relative orientation and distance of the object with respect to the stereo vision system. Due to its local characteristic, the present strategy can be implemented in a very inexpensive and simple digital or analog hardware scheme.