Hash-Based Block Matching for Nonsquare Blocks in Screen Content Coding

摘要

With the rapid development of electronic and multimedia technologies, screen contents are widely used in video related applications. However, hash-based block matching, one of the important coding tools designed to improve the coding efficiency of screen content video, is faced with the limitation of constrained block shapes. In this paper, based on the analysis of the time and storage complexity in adding nonsquare blocks to the latest block matching scheme, an improved block matching scheme is proposed by introducing two kinds of nonsquare blocks, i.e. 8 x 4 and 4 x 8 blocks to the coding tool, which can improve the coding efficiency and trade-off the efficiency and complexity. Compared with the latest HM-16.9+SCM-8.0, the proposed scheme achieves 1.47% and 0.94% bitrate saving in low delay and random access configurations with the cost of negligible encoding time increasing for all test text sequences.