Reduction of blocking artifacts using motion-compensated spatial-temporal filtering

An adaptive motion-compensated spatial-temporal filtering technique is presented. It is shown as an effective control parameter to gracefully tradeoff the quality of DCT coded video and bit rate in applications such as the MPEG video coding standard from digital storage media. Conventionally, spatial and temporal filters are used as fixed prefiltering parameters to reduce image resolution for coding and to eliminate background noise. This paper presents a new method to dynamically adjust the filters from the rate-control buffer. The filtering is performed over the motion path. Spatial filtering is also performed to provide smoother motion flow. Thus, a tradeoff of image quality and bit rate can be better balanced. By applying this feed-back control, the maximum image resolution is maintained for normal conditions while a graceful degradation is achieved for difficult scenes. Simulation results based on the MPEG video algorithm operating at .55 Mbit/sec and .95 Mbit/sec show that the proposed scheme is effective in alleviating block artifacts.