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30th Meeting: Antalya, TR, April 2023 2023-04-23 10:47
Non-EE2: Improved fixed filters for ALF
Authors: Marta Karczewicz Qualcomm Nan Hu Qualcomm Vadim Seregin Qualcomm
Abstract
In ECM-8.0, when applying adaptive loop filter (ALF) to a sample, two fixed filters with the corresponding Laplacian-based classifiers are firstly applied to the input of ALF. The outputs of the fixed filters are then used to derive ALF output. In this contribution, fixed filters are extended to be applied to the samples before deblocking filters. In addition, classifiers of the fixed filters are extended by using the differences between the mean value and the sample values. The proposed methods achieve 0.22%, 0.31% and 0.39% luma gain with similar encoding and decoding run time, in AI, RA and LDB configurations respectively over ECM-8.0. In addition, the outputs of the first fixed filter are used as the inputs to the second fixed filter, which can achieve estimated 0.32% luma gain in AI.
Meeting Notes
JVET-AD0220 Non-EE2: Improved fixed filters for ALF [M. Karczewicz, N. Hu, V. Seregin (Qualcomm)]

In ECM-8.0, when applying adaptive loop filter (ALF) to a sample, two fixed filters with the corresponding Laplacian-based classifiers are firstly applied to the input of ALF. The outputs of the fixed filters are then used to derive ALF output. In this contribution, fixed filters are extended to be applied to the samples before deblocking filters. In addition, classifiers of the fixed filters are extended by using the differences between the mean value and the sample values. The proposed methods achieve 0.22%, 0.31% and 0.39% luma gain with similar encoding and decoding run time, in AI, RA and LDB configurations respectively over ECM-8.0. In addition, the outputs of the first fixed filter are used as the inputs to the second fixed filter, which can achieve estimated 0.32% luma gain in AI.

The output of the filters is not fed into deblocking, it is applied to the non-deblocked samples before fceding them into ALF.

Several experts expressed interest.

It was agreed to investigate this in an EE.

ARCHIVE :
JVET-AD0220-Table1.xlsm JVET-AD0220-Table2.xlsm JVET-AD0220-v1.docx JVET-AD0220-v2-clean.docx JVET-AD0220-v2.docx JVET-AD0220.pptx
Decisions
It was agreed to investigate this in an EE.
Citation