Bilateral Loop Filter in Combination with SAO

Abstract

This paper describes a bilateral filter that is being proposed as a coding tool for the Versatile Video Codec (VVC). The filter acts as a loop filter in parallel with the sample-adaptive offset (SAO) filter. Both the proposed filter and SAO act on the same input samples, each filter produces an offset, and these offsets are then added to the input sample to produce an output sample that, after clipping, goes to the next stage. The method has been implemented and tested according to the common test conditions in VVC test model version 5.0. For the all-intra configuration, we report a BD rate figure of -0.4% with an encoder run time increase of 6% and a decoder run time increase of 4%. For the random access configuration, the BD rate figure is -0.5% with an encoder run time increase of 2% and a decoder run time increase of 2%.