A unified framework of hash-based matching for screen content coding

This paper introduces a unified framework of hash-based matching method for screen content coding. Screen content has some different characteristics from camera-captured content, such as large motion and repeating patterns. Hash-based matching is proposed to better explore the correlation in screen content, thus, improving the coding efficiency. The proposed method can handle both intra picture and inter picture block matching with variable block sizes in a unified framework. The proposed framework is also easy to be extended to handle other motion models to further improve the coding efficiency of screen content. We also develop fast encoding algorithms to make full use of the hash results. The experimental results show the proposed algorithm achieves about 12% bit saving while saving more than 25% encoding time. The bit saving is up to 57% and the encoding time saving is up to 60% for the proposed method.