  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).
