Contour-based multidirectional intra coding for HEVC
Thorsten Laude, Jörn Östermann · 2016
Intra coding is an indispensable part of all video coding systems. However, the intra prediction in the HEVC standard has several limitations with respect to the available amount of information which is exploited for the prediction and the limited number of prediction directions per block. In this paper, we propose a novel contour-based multidirectional intra coding mode which combines computer vision technologies with conventional video coding technologies to overcome these limitations. Structural parts and smooth parts of the video signal are predicted separately. While the structural parts are predicted based on contour detection, parameterization and extrapolation algorithms, the smooth areas are filled by means of low complexity technologies like sample value continuation. Thereby, the coding efficiency is considerably increased, with weighted average BD-rate gains of up to 1.9% compared to HM-16.3. A stand-alone codec implementation achieves average bit rate savings of 29.7% over JPEG and outperforms related work.