Organisation internationale de normalisation

9.4CE6c Edge based intra prediction

9.4.1.1.1.1.1.1.1JCTVC-D279 CE6.c: Summary and Improvements of DCIM [E. Maani, A. Tabatabai, T. Yamamoto]

This contribution presented a summary of DCIM Core Experiment (CE) results, its enhancements, and visual quality evaluation. Moreover, the results of additional experiments that demonstrate when DCIM is used, the maximum number of Unified Intra (UI) directions can reportedly be safely reduced from 34 to 17 with a slight improvement of average coding efficiency. More precisely, these experiments reportedly show that using 17 Intra directions with DCIM performs, on average, 2.3% and 2.6% better than the HM anchors with 34 Intra directions.

Prediction direction is determined by applying a Sobel edge detection

Encoding time increase 8%/15% Decoding time increase 6%/19% with 2.3%/2.6% for the HE/LC configs.

Subjective evaluation did not unveil improvement/degradation when video shown, but improvements in some frames.

Approximately 60% of the blocks use the mode currently.

The edge orientation is determined from a boundary stripe that is 4 pixels wide.

9.4.1.1.1.1.1.1.2JCTVC-D177 CE6.c: Cross-check report on Differential Coding of Intra Modes (DCIM) [Atsuro Ichigaya, Yasuko Sugito]

9.4.1.1.1.1.1.1.3JCTVC-D205 CE6: Cross-check report on differential coding of intra mode [K. Chono, K. Senzaki, H. Aoki, J. Tajime, Y. Senda]

9.4.1.1.1.1.1.1.4JCTVC-D218 CE6.c: cross verification of edge-based intra prediction [Virginie Drugeon]