JCTVC-M0453 Non-RCE2: Cross-check of JCTVC-M0439 on complexity reduction for residual DPCM in HEVC lossless coding [Y. H. Tan, C. Yeo (I2R)]
JCTVC-M0351 AHG8: Residual DPCM for visually lossless coding [R. Joshi, J. Sole, M. Karczewicz (Qualcomm)] [late]
Residual DPCM is being evaluated for lossless coding in Test 1 of RCE2. Extensions of residual DPCM have been proposed in JCTVC-M0288. In this document, the use of residual DPCM is proposed for lossy coding (targeting visually lossless coding). The method uses residual DPCM for certain intra modes when transform is skipped. Simulations results are presented for super-high tier QPs (12, 17, 22, and 27) using the test set and conditions recommended by AHG8. For the All-Intra configuration, it is reported that BD-rates of −2.1%, −2.1%, and −2.1% are achieved for the Y, U, and V components, respectively. For RGB 4:4:4 Screen Content sequences BD-rates of −3.7%, −3.5%, and −3.4% are reported.
The proposal includes TBA (presented)
lossy residual DPCM.
4% gain is claimed for applying to horizontal, vertical and near-horizontal and near-vertical for screen content. No gain on ordinary camera view content.
It was asked whether this applies to all TU sizes. It was only tested for 4x4 (since this is the only transform skip block size).
Sign data hiding is disabled (which may not be necessary, but that is what was done). This should be studied.
Cross-check in (late) M0444.
Further study in CE was suggested.
JCTVC-M0444 AHG8: Cross-check of JCTVC-M0351 [M. Naccari, A. Gabriellini, M. Mrak (BBC)] [late]
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