Cross-Color Channel Perceptually Adaptive Quantization for HEVC

Prangnell, Lee; Hernández-Cabronero, Miguel; Sánchez, Vı́ctor

doi:10.1109/dcc.2017.66

Cited by 2 publications

(2 citation statements)

References 8 publications

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“…Variables μCb and μCr are computed in (7) and (8), respectively: (8) where variables zCb and sCr refer to the m th raw sample and the i th raw sample in a Cb CB and a Cr CB, respectively. Similar to our work in [33], which is closely related to our work in [34,35], we exploit the CU-level chroma Cb and Cr CB QP offset signaling mechanism in the Picture Parameter Set (PPS) [36]. This facilitates a straightforward encoder side implementation of SC-PAQ and therefore ensures that the resulting bitstream conforms to the HEVC standard (i.e., ITU-T with Rec.…”

Section: Proposed Sc-paq Techniquementioning

confidence: 99%

JND-Based Perceptual Video Coding for 4:4:4 Screen Content Data in HEVC

Prangnell

Sánchez

2018

2018 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)

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The JCT-VC standardized Screen Content Coding (SCC) extension in the HEVC HM RExt + SCM reference codec offers an impressive coding efficiency performance when compared with HM RExt alone; however, it is not significantly perceptually optimized. For instance, it does not include advanced HVS-based perceptual coding methods, such as Just Noticeable Distortion (JND)-based spatiotemporal masking schemes. In this paper, we propose a novel JND-based perceptual video coding technique for HM RExt + SCM. The proposed method is designed to further improve the compression performance of HM RExt + SCM when applied to YCbCr 4:4:4 SC video data. In the proposed technique, luminance masking and chrominance masking are exploited to perceptually adjust the Quantization Step Size (QStep) at the Coding Block (CB) level. Compared with HM RExt 16.10 + SCM 8.0, the proposed method considerably reduces bitrates (Kbps), with a maximum reduction of 48.3%. In addition to this, the subjective evaluations reveal that SC-PAQ achieves visually lossless coding at very low bitrates. Table 1: The bitrate reductions (in bold green text) achieved by SC-PAQ compared with anchors: HM 16.10 + SCM 8.0 (left) and IDSQ [16] (right).

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Section: Proposed Sc-paq Techniquementioning

confidence: 99%

JND-Based Perceptual Video Coding for 4:4:4 Screen Content Data in HEVC

Prangnell

Sánchez

2018

2018 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)

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“…FCPQ expands on our previously proposed method, known as Color-Based Adaptive Quantization (C-BAQ) [16], which is a cross-color channel CU-level perceptual quantization technique based on the technical principles of AdaptiveQP. C-BAQ adjusts the QP of an entire 2N×2N CU by computing the sum of all pixel variances in the corresponding luma and chroma CBs, which equates to cross-color channel dependency for QP selection; FCPQ is designed to improve upon C-BAQ.…”

Section: Proposed Fcpq Technique For Hevcmentioning

confidence: 99%

Coding block-level perceptual video coding for 4:4:4 data in HEVC

Prangnell

Hernández-Cabronero

Sánchez

2017

2017 IEEE International Conference on Image Processing (ICIP)

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There is an increasing consumer demand for high bit-depth 4:4:4 HD video data playback due to its superior perceptual visual quality compared with standard 8-bit subsampled 4:2:0 video data. Due to vast file sizes and associated bitrates, it is desirable to compress raw high bit-depth 4:4:4 HD video sequences as much as possible without incurring a discernible decrease in visual quality. In this paper, we propose a Coding Block (CB)-level perceptual video coding technique for HEVC named Full Color Perceptual Quantization (FCPQ). FCPQ is designed to adjust the Quantization Parameter (QP) at the CB level -i.e., the luma CB and the chroma Cb and Cr CBs -according to the variances of pixel data in each CB. FCPQ is based on the default perceptual quantization method in HEVC called AdaptiveQP. AdaptiveQP adjusts the QP of an entire 2N×2N CU based only on the spatial activity of the constituent luma CB. As demonstrated in this paper, by not accounting for the spatial activity of the constituent chroma CBs, as is the case with AdaptiveQP, coding performance can be significantly affected; this is because the variance of pixel data in a luma CB is notably different from the variances of pixel data in chroma Cb and Cr CBs. FCPQ, therefore, addresses this problem. In terms of coding performance, FCPQ achieves BD-Rate improvements of up to 39.5% (Y), 16% (Cb) and 29.9% (Cr) compared with AdaptiveQP.

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Cross-Color Channel Perceptually Adaptive Quantization for HEVC

Cited by 2 publications

References 8 publications

JND-Based Perceptual Video Coding for 4:4:4 Screen Content Data in HEVC

JND-Based Perceptual Video Coding for 4:4:4 Screen Content Data in HEVC

Coding block-level perceptual video coding for 4:4:4 data in HEVC

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