Preprocessing of video for compression

Abstract

This paper addresses the issue of introducing information loss in a video sequence prior to coding with the objective of maintaining visual quality while lowering the bit rate required to code the video. We argue that managing perceptually meaningful information if better accomplished in the motion domain rather than the pixel intensity domain. Based on recent advances in motion estimation and modeling, we introduce a representation of video data using motion information wherein every frame of a sequence is replaced with a field of interframe correspondences. Knowledge of the previous frame along with the filed of interframe correspondences is sufficient to reconstruct the current frame. Preprocessing is accomplished by filtering interframe correspondences and generating processed video using the filtered correspondence field. Simulations using the MPEG video coding standard reveal that rate gains of up to 20 percent are possible when filtering such that the processed and original video are of similar visual quality.