rgb_to_lab — IMGMETRICS colorspace op

• Data kinds: rgbimage → lab

• Call: import imgmetrics; imgmetrics.rgb_to_lab(rgb, white=(0.95047, 1.0, 1.08883)) (or opsimgmetrics.get("rgb_to_lab"))

Usage

sRGB → CIE L\*a\*b\* (D65). The step before measuring ΔE.

Detailed usage guide

• image_difference_metrics family guide

Background guides (the physics and conventions behind this op)

• colorimetry — 測色と分光の知識 — 色は「分光 × 光源 × 観測者」でしか決まらない

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 lab as input)

lab_to_rgb · delta_e_2000 · delta_e_76

Same category (colorspace)

lab_to_rgb · rgb_to_xyz · xyz_to_lab

*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.