Visually Lossless Coding in HEVC: A High Bit Depth and 4:4:4 Capable JND-Based Perceptual Quantisation Technique for HEVC

TL;DR

This paper introduces Pixel-PAQ, a JND-based perceptual quantization technique for HEVC that effectively compresses high bit depth 4:4:4 video data while maintaining visually lossless quality, significantly reducing bitrate.

Contribution

Pixel-PAQ is a novel CB-level JND-based perceptual quantization method for HEVC, capable of handling high bit depth 4:4:4 data and outperforming existing techniques in bitrate reduction.

Findings

Achieves up to 75% bitrate reduction compared to IDSQ.

Successfully maintains visually lossless quality at PSNR of 28.04 dB.

Compatible with high bit depth YCbCr 4:4:4 video data.

Abstract

Due to the increasing prevalence of high bit depth and YCbCr 4:4:4 video data, it is desirable to develop a JND-based visually lossless coding technique which can account for high bit depth 4:4:4 data in addition to standard 8-bit precision chroma subsampled data. In this paper, we propose a Coding Block (CB)-level JND-based luma and chroma perceptual quantisation technique for HEVC named Pixel-PAQ. Pixel-PAQ exploits both luminance masking and chrominance masking to achieve JND-based visually lossless coding; the proposed method is compatible with high bit depth YCbCr 4:4:4 video data of any resolution. When applied to YCbCr 4:4:4 high bit depth video data, Pixel-PAQ can achieve vast bitrate reductions, of up to 75% (68.6% over four QP data points), compared with a state-of-the-art luma-based JND method for HEVC named IDSQ. Moreover, the participants in the subjective evaluations confirm that visually lossless coding is successfully achieved by Pixel-PAQ (at a PSNR value of 28.04 dB in one test).