Screen content coding for HEVC by improved line-based intra block copy

The line-based intra block copy (IntraBC) technique is newly proposed in the High Efficient Video Coding (HEVC) Range Extensions to deal with repeated patterns within a picture for screen content coding. One challenge for line-based IntraBC is the large overhead by transmitting displacement vectors (DV) for each line. In this paper, a DV prediction is proposed to reduce such an overhead. Moreover, a flipping copy based prediction is proposed to better exploit the correlations within screen content. Experimental results show that our scheme can provide a BD-rate reduction of 11.0% compare with the HEVC Range Extension anchor with the encoding time increased by 23% and no decoding time increase.