Organisation internationale de normalisation

16.2Contributions

16.2.1.1.1.1.1.1.1JCTVC-D282 CE13: Mode Dependent Hybrid Intra Smoothing [Yunfei Zheng, Muhammed Coban, Marta Karczewicz]

In this contribution, a mode dependent hybrid intra smoothing scheme was proposed to improve the coding performance. In the proposed scheme, a hybrid approach which combines the mode dependent filter selection and explicit filter signaling is used to select a filter for smoothing the prediction samples. The proposed scheme reportedly results in 0.5% and 0.9% BD BR reduction on average for high efficiency and low complexity intra configuration respectively. The average encoding/decoding time has no significant change comparing to TMuC 0.9’s default setting.

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  3 options: no filter, filter1, filter2
  
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  Which filter is used, is derived by two LUTs (most probable filter) from the mode and the PU block size
  
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  For 4x4 and 8x8 only one LUT is used, otherwise it is signalled which one to use.
  
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  For RD opt., only LUT1
  
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  Without LUT signalling (using only LUT1), the gain is 0.3% and 0.7% for HE and LC
  
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  Visual tests? It is said that visual differences are hardly visible
  
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  Current LUTs also contain entries 128x128, should be removed
  

16.2.1.1.1.1.1.1.2JCTVC-D103 CE13: Cross check report of Qualcomm's proposal (JCTVC-D282) from Toshiba [Akiyuki Tanizawa, Taichiro Shiodera (Toshiba)]

16.2.1.1.1.1.1.1.3JCTVC-D176 CE13: Cross-verification of Qualcomm’s simplified intra smoothing [J. Chen, J.-H. Min, W.-J. Han(Samsung)]

16.2.1.1.1.1.1.1.4JCTVC-D305 CE13: Cross-Check Result of 3.2d [Kazushi Sato] (initial version rejected as a placeholder upload)

16.2.1.1.1.1.1.1.5JCTVC-D313 CE13: Intra Smoothing Test Report [B. Bross, D. Marpe, H. Schwarz, T. Wiegand (Fraunhofer HHI)]

This document reports results of core experiment 13 evaluating intra smoothing tools. Two of the four tested tools perform intra reference sample smoothing based on a mode and block size dependent lookup table. The other two combine the lookup table with signaling. For the best performing tool, encoding times from 101% (intra low complexity) to 97% (low delay low complexity) of the anchor times, decoding times around 98% of the anchor times with bit rate savings from 0.87% (intra low complexity) to -0.04% (low delay low complexity) are reported.

With average bit rate savings between 0.48% and 0.85% for intra only and no significant differences in encoding/decoding time, it was suggested to be concluded that the mode dependent hybrid intra smoothing (MDHIS) is the preferred intra smoothing tool.

16.2.1.1.1.1.1.1.6JCTVC-D208 CE13: Cross-check report on HHI adaptive intra smoothing [K. Chono, K. Senzaki, H. Aoki, J. Tajime, Y. Senda]

16.2.1.1.1.1.1.1.7JCTVC-D363 CE13: cross-verification on HHI’s fast adaptive intra smoothing [J. Chen, J.-H. Min (Samsung)]

16.2.1.1.1.1.1.1.8JCTVC-D402 CE13: Intra Smoothing Test Report [M. Coban, Y. Zheng, M. Karczewicz]