PSNR-HVS¶

PSNR-HVS (Peak Signal-to-Noise Ratio - Human Visual System) extends traditional PSNR with contrast sensitivity function (CSF) weighting applied in the DCT domain, making it more sensitive to perceptually significant distortions.

Variants¶

Extractor name	Algorithm	Options
`psnr_hvs`	CSF-weighted DCT-domain PSNR	`enable_chroma`

`psnr_hvs` extractor¶

The extractor computes PSNR in the 8x8 DCT domain with per-coefficient weighting derived from a human visual system contrast sensitivity model (Ponomarenko et al.). It is the extractor invoked when VMAF model JSON files reference "psnr_hvs".

Output features¶

Feature name	Description	Condition
`psnr_hvs`	HVS-weighted PSNR on the luma (Y) plane	Always
`psnr_hvs_cb`	HVS-weighted PSNR on the Cb (U) plane	`enable_chroma=true` only
`psnr_hvs_cr`	HVS-weighted PSNR on the Cr (V) plane	`enable_chroma=true` only

Options¶

enable_chroma (bool, default false): emit per-plane _cb and _cr scores in addition to luma. YUV400P sources are always luma-only.

How to run¶

# Luma-only PSNR-HVS (default)
core/build/tools/vmaf \
    --reference ref.yuv --distorted dist.yuv \
    --width 1920 --height 1080 --pixel_format 420 --bitdepth 8 \
    --no_prediction --feature psnr_hvs --output /dev/stdout

# Per-channel PSNR-HVS (luma + Cb + Cr)
core/build/tools/vmaf \
    --reference ref.yuv --distorted dist.yuv \
    --width 1920 --height 1080 --pixel_format 420 --bitdepth 8 \
    --no_prediction --feature 'psnr_hvs:enable_chroma=true' --output /dev/stdout

Backend parity (chroma plane dimensions)¶

psnr_hvs runs on CPU, CUDA, HIP, and SYCL with runtime backend selection. For chroma planes (enable_chroma=true) on subsampled formats (YUV420 / YUV422) whose luma width or height is odd, each chroma plane dimension is the ceiling of the half-resolution, not the floor — e.g. a 1921-wide 4:2:0 frame has a 961-sample-wide chroma plane ((1921 + 1) / 2), not 960. All backends compute the ceiling so that psnr_hvs_cb / psnr_hvs_cr agree across CPU / CUDA / HIP / SYCL on odd-dimension frames. (The SYCL path previously floored the chroma dimensions, dropping the last chroma column/row on odd inputs and diverging from the other backends.)