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29th Meeting: by teleconference, DE, January 2023 2023-01-17 01:09
Non-EE2: Template Matching for RR-IBC
Authors: CHUN-CHI CHEN Qualcomm Han Huang Qualcomm Zixiang Zhang Qualcomm Vadim Seregin Qualcomm Marta Karczewicz Qualcomm
Abstract
This contribution proposes to extend template matching (TM) to RR-IBC (reconstruction-reordering intra block copy). In ECM-7.0, template matching is applied to TM AMVP and TM MRG modes of IBC only when flipping is disabled for IBC blocks. This contribution enables TM, that ECM-7.0 uses currently, for IBC CU’s with horizontal or vertical flipping type. Firstly, the template blocks are flipped horizontally or vertically before template matching cost is computed, and then the search process of template matching can be reused completely for BV refinement. Experimental results are summarized below.
Meeting Notes
JVET-AC0169 Non-EE2: Template Matching for RR-IBC [C.-C. Chen, H. Huang, Z. Zhang, V. Seregin, M. Karczewicz (Qualcomm)]

This contribution proposes to extend template matching (TM) to RR-IBC (reconstruction-reordering intra block copy). In ECM-7.0, template matching is applied to TM AMVP and TM MRG modes of IBC only when flipping is disabled for IBC blocks. This contribution enables TM, that ECM-7.0 uses currently, for IBC CU’s with horizontal or vertical flipping type. Firstly, the template blocks are flipped horizontally or vertically before template matching cost is computed, and then the search process of template matching can be reused completely for BV refinement. Experimental results are summarized below.

  • AI Class F : (Y) -0.05%, (U) 0.13%, (V) 0.11%, (EncT) 100%, (DecT) 100%
  • AI Class TGM : (Y) -0.03%, (U) 0.01%, (V) -0.02%, (EncT) 100%, (DecT) 100%
  • RA Class F : (Y) -0.07%, (U) -0.34%, (V) -0.04%, (EncT) 100%, (DecT) 99%
  • RA Class TGM: (Y) 0.02%, (U) -0.10%, (V) 0.06%, (EncT) 101%, (DecT) 100%
  • LB Class F : (Y) -0.25%, (U) -0.38%, (V) -1.21%, (EncT) 100%, (DecT) 100%
  • LB Class TGM: (Y)-0.04%, (U) 0.11%, (V) 0.13%, (EncT) 100%, (DecT) 101%

It was asked if by removing the conditional checks, more template matching would have to be performed. It was commented by the proponent that the proposed method does not increase the amount of template matching that the decoder performs. The asserted inconsistency was introduced when RR-IBC was adopted.

It was commented that the gains for the SCC classes are rather low, some loss in class TGM in RA configuration.

No action was taken on this at this time.

Cited:
JVET-AC0207 X
ARCHIVE :
JVET-AC0169-v1.docx JVET-AC0169-v1.pdf JVET-AC0169-v1.xlsm
Decisions
No action was taken on this at this time.
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