Direct estimation of multiple disparities for transparent multiple surfaces in binocular stereo

A closed-form single-shot stereo disparity estimation algorithm is proposed that can compute multiple disparities due to transparency directly from signal differences and variations on epipolar lines of a binocular image pair. The transparent stereo constraint equations have been derived by using a novel mathematical technique, the principle of superposition. A computationally tractable single-shot algorithm is derived by using the first-order approximation of the constraint equations with respect to disparities. The algorithm can compute multiple disparities from only two images, in contrast to the previous algorithms for motion transparency, which needed at least n+1 frames for n simultaneous motion estimates. The derived algorithm can be viewed as the SSD (sum of squared differences) for signal matching extended to deal with multiple disparities. However, the constraints are not dedicated solely to the SSD method and several other implementations are possible