<title>Improved disparity estimation for the coding of stereoscopic television</title>

Abstract

An algorithm is presented that computes the disparity vector fields of arbitrary stereo image sequences with high accuracy and without the assumption of a known camera geometry. The disparity vectors are used for the reconstruction of the right image sequence from the left one in a 3DTV transmission system, thus replacing the full transmission of both stereo channels by a stereocompensated scheme. Compared to classical approaches in robot vision, however, the disparity vector fields have to be dense and sufficiently smooth while maintaining high accuracy to allow for efficient coding and good reconstruction quality. Related to the overlying source coding scheme the analysis still rests block-based. An initial estimate of the disparity is obtained by a correlation of the image phase. Combining an analysis of texture variance and contour information then either a re-estimation using a more sophisticated image analysis or a surface interpolation is applied to selected regions of high reconstruction error. In regions of sufficient texture structures on additional differential identification of affine or quadratic block models is performed. Continuity versus time and ordering constraints from stereopsis serve as further optimization criterions.