Synthesis Of Fine Details In B Picture For Dynamic Textures

Dynamic textures are characterized with irregular motions that are often challenging for motion compensation as applied in the state of the art video codecs. Due to rapid and randomly evolving nature of such a signal, it is accompanied with very high energy in the residual. As a result, B-pictures as used in HEVC layer are relative expensive to code. This leads to an overall increase in the bitrate. Further, increasing QP(offset) worsens the quality by forcing lower rate to these B-pictures, leading to strong blurring and blocking artefacts. In this paper, we exploit Steerable Pyramid (SP) for coding pictures with t(id) > 2 in a downsampled format. At the decoder side, details are synthesized for these low resolution pictures by adding back the high frequencies using motion compensation from the nearest key picture followed by an inverse SP transform. The paper synthesizes details for the dynamic textures that are expensive to code. Our investigation shows up to 31% saving in bitrate, while visual quality is kept acceptable.