| 主权项 |
1. A computer-implemented stereo image processing method comprising, at a processor:
performing a contour extraction process on first and second silhouette images, captured by a stereo camera, of at least part of an object in a scene, to produce respective first and second pluralities of contour points, each plurality of contour points defining a contour of the at least part of the object; calculating stereo correspondences between contour points on corresponding scanlines in the first and second pluralities of contour points on the basis of contour point comparison metrics; and at least one of:
for each of a number of corresponding scanlines:
identifying a first set of contour points which lie in the scanline in the first plurality of contour points and a second set of contour points which lie in the scanline in the second plurality of contour points;obtaining one or more comparison metrics for each contour point;comparing the one or more comparison metrics of each of the first set of contour points with the one or more comparison metrics of each of the second set of contour points to produce a cost matrix; andcomputing a minimum-cost path through the cost matrix to calculate the stereo correspondences between the first set of contour points and the second set of contour points; orfor each of a number of corresponding scanlines:
identifying a first set of contour points which lie in the scanline in the first plurality of contour points and a second set of contour points which lie in the scanline in the second plurality of contour points;obtaining one or more comparison metrics for each contour point;comparing the one or more comparison metrics of each of the first set of contour points with the one or more comparison metrics of each of the second set of contour points to produce a cost matrix; andcomputing a minimum-cost path through the cost matrix to calculate the stereo correspondences between the first set of contour points and the second set of contour points; andat least one of:
the one or more comparison metrics comprising a measure of direction of curvature of the contour; orthe one or more comparison metrics comprising a unit normal vector representing each contour point and comparing comparison metrics comprising calculating, for each pair of contour points in the cost matrix, a magnitude of the resultant vector obtained by subtracting the unit normal vector for one of the pair of contour points from the unit normal vector for the other of the pair of contour points; orthe one or more comparison metrics comprising a centroid separation, comprising a distance along the scanline between each contour point and a centroid of a contour on which the contour point lies, and comparing comparison metrics comprising calculating, for each pair of contour points in the cost matrix, a magnitude of the difference between the centroid separation for one of the pair of contour points and the centroid separation for the other of the pair of contour points; orproducing the cost matrix comprising using a smoothing term to adjust the cost for each pair of contour points in the cost matrix, the smoothing term being the difference between the separation of one of the contour points in the Pair from its closest neighboring contour point and the separation of the other of the contour points in the pair from its closest neighboring contour point; orobtaining a depth map based at least in part on the first and second pluralities of contour points and at least one of:
invalidating contour points which lie in separate, adjacent scanlines along a contour in the depth map and whose depth differs by more than a predetermined amount; orsmoothing depth values along a contour in the depth map; orassigning depth values to occluded contour points, invalidated contour points, or both. |
