Inter-layer intra mode prediction for scalable extension of HEVC

This paper introduces a novel inter-layer intra mode prediction method for scalable extension of High Efficiency Video Coding (HEVC) standard, which is being developed by the Joint Collaborative Team on Video Coding (JCT-VC). In HEVC and its scalable extension, thirty-five intra prediction modes are adopted to reduce the spatial redundancy of luma texture within one frame, which may introduce noticeable overhead of delivering the intra mode information in the scalable bit-stream. In this paper, the correlation of intra modes between different layers is exploited to improve the efficiency of intra mode coding in enhancement layer. The intra modes in enhancement layer are mainly predicted with the ones of collocated blocks at base layer. Two techniques are presented in this paper with some differences in terms of the derivation of intra mode predictor from base layer and the selection of three most probable modes at enhancement layer. Compared to Test Model version 1.0 of HEVC scalable extension, 0.4% and 0.1% bit-rate reductions can be achieved with technique 2 in All Intra 2x spatial scalability and All Intra 1.5x spatial scalability respectively, while technique 1 can achieve 0.2% and 0.1% reductions. There is no obvious running time increase for both encoder and decoder.