Reciprocal-wedge transform in motion stereo

The reciprocal-wedge transform (RWT) facilitates space-variant sensing which enables effective use of variable-resolution data and the reduction of total amount of the sensory data. This paper presents two motion stereo methods that exploit the important properties of the RWT, i.e., the anisotropic variable resolution and the preservation of linear features. It is shown that the RWT is suitable for the correspondence process in both lateral and longitudinal motion stereo which deal with disparities of corresponding features along epipolar lines. Multiple frames of motion stereo images are employed to improve precision and error rate of the depth recovery. In the lateral motion stereo the RWT is applied in both space and time domains to transform the x-t epipolar plane in ordinary motion stereo images into a new ω-τ epipolar plane. In the longitudinal motion stereo, the reciprocity of the RWT restores the nonlinearity in the original x-t epipolar plane. Consequently, in both cases, the correspondence problem in variable-resolution motion stereo is reduced to a simpler problem of extracting collinear points in the epipolar plane. A voting algorithm for accumulating multiple evidence is developed. The proposed method is potentially applicable to active sensing for automated inspection on assembly lines, autonomous road vehicle navigation, airport runway surveillance, etc. Preliminary experimental results are demonstrated