Detail-Aware Image Decomposition for an HEVC-Based Texture Synthesis Framework

Abstract

Modern video coding standards like High Efficiency Video Coding (HEVC) provide superior coding efficiency. However, this does not state true for complex and hard to predict textures which require high bit rates to achieve a high quality. To overcome this limitation of HEVC, texture synthesis frameworks were proposed in previous works. However, these frameworks only result in good reconstruction quality if the decomposition into synthesizable and non-synthesizable regions is either known or trivial. The frameworks fail for more challenging content, e.g. for content with fine non-synthesizable details within synthesizable regions. To enable texture synthesis-based video coding with high quality for this content, we propose sophisticated detail-aware decomposition techniques in this paper. These techniques are based on an initial coarse segmentation step followed by a refinement step that detects even small differences in the previously segmented region. With this new approach, we are able to achieve average luma BD-rate gains of 13.77% over HEVC and 3.03% over the closest related work from the literature. Furthermore, the considerably improved visual quality in addition to the bit rate savings is confirmed by comprehensive subjective tests.