Modified predictive motion estimation for reduced-resolution video from high-resolution compressed video

To convert a compressed video sequence to a lower-resolution compressed video, one typically needs to decompress the original sequence, down-sample each frame, and recompress it. It involves motion estimation in the reduced sequence which is computational intensive. Predictive motion estimation was proposed to generate the motion vectors of the reduced video by using the original motion information in the compressed bitstream. However, it was described only for the case of 4 to 1 down-conversion. In this paper, we propose a modified predictive motion estimation to work on other down-conversion ratios at lower complexity