psnr — IMGMETRICS fidelity op

• Data kinds: image2d × image2d → scalar

• Call: import imgmetrics; imgmetrics.psnr(a, b, data_range=None) (or opsimgmetrics.get("psnr"))

Usage

Peak signal-to-noise ratio [dB].

> The detailed description below is the original text — the summary and the headings are translated.

完全に一致する 2 枚では **`inf`** を返す(0 除算を黙って回避するために

小さな値を足したりしない ―― それは「非常に良い一致」を有限の数値に化かし、

平均を取ったときに嘘になる)。

`data_range の決め方は :func:data_range_of` を参照。

Detailed usage guide

• image_difference_metrics family guide

References (sample data, literature)

• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).

• Operator provenance and references — the sources of the research/methods this op family came from.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Runnable examples (verified samples that actually call this op)

• image_quality_metrics — py -3.11 examples/image_quality_metrics.py

Ops the type connects to (they accept scalar as input)

—

Same category (fidelity)

mse · rmse · ssim · ms_ssim · ssim_map

*Provenance: imgmetrics.py — IMGMETRICS operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.