METHOD AND APPARATUS FOR HIERACHICAL MOTION ESTIMATION IN THE PRESENCE OF MORE THAN ONE MOVING OBJECT IN A SEARCH WINDOW

摘要

In hierarchical motion estimation motion vectors are refined in successive levels of increasing search window pixel density and/or decreasing search window size. Within each hierarchical level, after finding an optimum vector at at least one pixel, based on the optimum vector, the absolute displaced frame difference or displaced frame difference for each pixel of the search window is determined. Within the search window, two or more groups of these pixels are determined, wherein each of these pixel groups is characterized by a different range of absolute displaced frame difference values or displaced frame difference values for the pixels. A segmentation of the search window into different moving object regions is carried out by forming pixel areas according to the groups, which areas represent a segmentation mask for the search window. For at least one of the segmentation areas a corresponding motion vector is estimated.

主权项

1. A method for hierarchical motion estimation in which motion vectors are refined in successive levels of increasing measurement window pixel density and/or decreasing measurement window size, comprising:
within each hierarchical level, after finding an optimum vector at at least one pixel in a frame, determining based on said optimum vector the displaced frame difference DFD or absolute displaced frame difference |DFD| for each pixel of the measurement window; determining within said measurement window two or more groups of pixels, wherein each of these pixel groups is characterized by a different range of displaced frame difference values or absolute displaced frame difference values for the pixels; carrying out a segmentation of the measurement window into different moving object regions by forming pixel areas according to said groups, which areas represent a segmentation mask for the measurement window; estimating for at least one of said segmentation areas a corresponding motion vector.