delta_e_2000 — IMGMETRICS `colordiff` op

• Data kinds: lab × lab → image2d

• Call: import fullseye as fs; fs.ledger.delta_e_2000(lab1, lab2, kL=1.0, kC=1.0, kH=1.0) (to call the implementation directly, import imgmetrics; imgmetrics.delta_e_2000(lab1, lab2, kL=1.0, kC=1.0, kH=1.0); from the registry, opsimgmetrics.get("delta_e_2000"))

Usage

CIEDE2000 colour difference (CIE 142-2001).

The 3 places where implementations tend to slip -- the mean hue angle (handling the 0/360 wrap), the 275° rotation term, and near-zero chroma (handling atan2(0, 0)) -- are pinned with the 34 verification pairs of Sharma, Wu & Dalal (2005) (CIEDE2000_TEST_PAIRS / tests/test_imgmetrics.py).

Parameters

lab1, lab2 : array_like

Arrays whose last axis is (L*, a*, b*). They are broadcast.

kL, kC, kH : float

Parametric factors for viewing conditions. The default is 1, the reference condition.

Returns

ndarray

ΔE00 (with the last axis dropped).

Detailed usage guide

• image_difference_metrics family guide

Background guides (the physics and conventions behind this op)

• colorimetry — Colorimetry and spectra — colour is fixed only by spectrum × illuminant × observer

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 `image2d` as input)

mse · rmse · psnr · ssim · ms_ssim · ssim_map · image_entropy · joint_entropy

Same category (`colordiff`)

delta_e_76 · delta_e_map

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

delta_e_2000 — IMGMETRICS colordiff op