METHOD AND APPARATUS FOR REDUCING THE MEMORY REQUIREMENT FOR DETERMINING DISPARITY VALUES FOR AT LEAST TWO STEREOSCOPICALLY RECORDED IMAGES

摘要

A method and an apparatus for reducing the temporary random access memory when determining disparity values for at least two stereoscopically recorded images (B1', B2') with known epipolar geometry, in which a disparity (dmin) is determined for each pixel (P1) of a first image (B1'), in that path-dependent dissimilarity costs are calculated on the basis of a disparity-dependent cost function, and are compared, in at least two runs for a number (K) of paths which open in the pixel (P1), wherein the disparity-dependent cost function evaluates at least one pixel-based dissimilarity measure between the pixel (P1) and the corresponding pixel (P2), according to the respective disparity, in a second image (B2'), wherein the path-dependent dissimilarity costs for a first predetermined set (D) of disparities are calculated in a first run for a number of first paths (k1 = 1 ... M) and in a second run for a number (k2=M+1...K) of remaining paths, and the corresponding path-dependent dissimilarity costs of the first paths and of the remaining paths are accumulated for a second predetermined set (N) of disparities, wherein the resultant disparity (dmin) is determined as a disparity for which an accumulation of path-dependent dissimilarity costs has a minimum, wherein the second set (N) of disparities is less than the first predetermined set (D) of disparities, wherein the second set (N) of disparities contains at least one disparity at which the path-dependent dissimilarity costs of at least one first path have a minimum of the path-dependent dissimilarity costs and/or a disparity at which the path-dependent dissimilarity costs of at least one remaining path have a minimum of the path-dependent dissimilarity costs, or the second set (N) of disparities contains at least one disparity which is removed in a predetermined manner from a disparity at which the path-dependent dissimilarity costs of at least one first path have a minimum of the path-dependent dissimilarity costs, and a disparity which is removed in a predetermined manner from a disparity at which the path-dependent dissimilarity costs of at least one remaining path have a minimum of the path-dependent dissimilarity costs, wherein the accumulation of corresponding path-dependent dissimilarity costs is carried out following the first run for the second predetermined set (N) of disparities.