delta_e_map — IMGMETRICS colordiff op

Data kinds: rgbimage × rgbimageimage2d

Call: import fullseye as fs; fs.ledger.delta_e_map(rgb1, rgb2, kind='2000', white=(0.95047, 1.0, 1.08883)) (to call the implementation directly, import imgmetrics; imgmetrics.delta_e_map(rgb1, rgb2, kind='2000', white=(0.95047, 1.0, 1.08883)); from the registry, opsimgmetrics.get("delta_e_map"))

Usage

Per-pixel colour-difference map between two sRGB images.

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

RGB の平均二乗誤差ではなく知覚的な色差で見るための入口。

`kind"2000"(既定)または "76"`。

手順: 2 枚を `rgb_to_lab(·, white) で Lab にし、kind="2000"` なら

`delta_e_2000(CIEDE2000、kL = kC = kH = 1)、"76" なら delta_e_76`

(Lab のユークリッド距離)を画素ごとに取る。

• `rgb1, rgb2: 同じ形で ndim >= 3、最後の軸が 3((H, W, 3)`)。

整数 dtype は dtype の最大値で正規化、float は `[0, 1] 必須(rgb_to_xyz`

の契約)。線形 RGB ではなく sRGB を渡す。

• `white`: Lab の白色点(既定 D65)。

• 返り値: `(H, W)` の float64。0 が同一色。平均を取れば画像全体の指標になる

(`compare_imageschannel_axis を渡すと delta_e_2000_mean` として入る)。

• 失敗(`MetricContractError): kind` が上記以外 / 形が違う / 3 チャネルでない

/ float が `[0, 1] の外。グレー (H, W)` は受けない。

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)

color_transportpy -3.11 examples/color_transport.py

image_quality_metricspy -3.11 examples/image_quality_metrics.py

poc_colormap_readabilitypy -3.11 examples/poc_colormap_readability.py

poc_pigment_unmixingpy -3.11 examples/poc_pigment_unmixing.py

poc_white_balancepy -3.11 examples/poc_white_balance.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_2000 · delta_e_76


*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.