Bilateral filtering for video coding

This paper proposes the use of a bilateral filter as a coding tool for video compression. The filter is applied after transform and reconstruction, and the filtered result is used both for output as well as for spatial and temporal prediction. The implementation is based on a look-up table (LUT), making it fast enough to give a reasonable trade-off between complexity and compression efficiency. By varying the center filter coefficient and avoiding storing zero LUT entries, it is possible to reduce the size of the LUT to 2202 bytes. It is also demonstrated that the filter can be implemented without divisions, which is important for full custom ASIC implementations. The method has been implemented and tested according to the common test conditions in JEM version 5.0.1. For still images, or intra frames, we report a 0.4% bitrate reduction with a complexity increase of 6% in the encoder and 5% in the decoder. For video, we report a 0.5% bitrate reduction with a complexity increase of 3% in the encoder and 0% in the decoder.