Fast computation of motion vectors for MPEG
Navid Haddadi, C.‐C. Jay Kuo · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1993
Motion compensated video coding in the MPEG standard relies on the knowledge of a single motion vector per 16 X 16 block of pixels called the macroblock. While a brute force approach known as the full search block matching algorithm (BMA) or its variations has been commonly adopted in computing the motion vector in most implementations of the MPEG standard, we study a gradient based method in this work. The proposed method is based on our previous results on multiresolution computation of a discontinuous optical flow field, and some modifications are introduced in this research for efficient computation. Classical motion compensated coding methods approximate the motion field with a piecewise constant function. In contrast, our algorithm approximates the motion field by a piecewise linear function over small triangular subregions. Hence, the resulting algorithm is not only attractive from a computational point of view, but also it provides a better model of the motion field which may result in better compression factors than BMA. Experimental results on some standard test images are reported.