Fast and efficient intra coding techniques for smooth regions in screen content coding based on boundary prediction samples

This paper presents fast and efficient intra prediction algorithms for screen content coding (SCC). The proposed algorithms focus on smooth regions frequently appeared in screen content videos, which have the characteristics of noiselessness. All the samples in a noiseless smooth region exhibit exactly the same pixel value. We then propose two intra coding techniques for noiseless smooth regions in SCC based on the smoothness of the boundary samples which are used for intra prediction. Our proposed algorithm can reduce computational complexity by at most 26.7% while keeping nearly the same video quality. Moreover, by removing the redundant coding bits for intra prediction modes, computational complexity can be further reduced to at most 53.3% in terms of encoding time with bitrate reduction up to 1.2%.