specular_free_transform — SPECULAR dichromatic op

• データ種: rgbimage → rgbimage

• 呼び出し: import specularity; specularity.specular_free_transform(image_rgb, illuminant_rgb=(1.0, 1.0, 1.0)) (または opsspecular.get("specular_free_transform"))

使い方

Project out the illuminant direction: the part of the image a highlight cannot touch. → (H, W, 3).

`I - (I.G) G for the unit illuminant colour G`. Under the dichromatic

model the interface term is `m_s * G`, so it lies entirely in the removed

direction and the result is invariant to any specular term whatsoever —

exactly, for any lobe shape, any strength, any spatial pattern. That is the

specular-invariant subspace of Mallick et al. (2005); this operator is the

projection itself, with no rotation into named channels, so it stays in RGB

and composes with the rest of the family.

Use it when the *shape* of the specular lobe is unknown or the surface is

textured — feature matching, edge detection and correlation all work in this

subspace without any of the assumptions

:func:specular_diffuse_split needs.

This is a projection, not a picture. The result loses one of three

degrees of freedom (its component along `G` is exactly zero everywhere)

and, for an image with negative values after black-level subtraction, keeps

them. It is not a displayable "highlight-removed photo" and does not claim

to be; for that, use :func:specular_diffuse_split.

Raises `ValueError: *image_rgb* is not a valid (H, W, 3)` linear

RGB image (see :func:specular_diffuse_split); *illuminant_rgb* is not a

non-zero 3-vector.

詳しい使い方ガイド

• specular_photometric ファミリ ガイド

参考(サンプルデータ・文献)

• サンプルデータ カタログ(DL URL / ライセンス) — 2-D は skimage.data(BSD/public)+ 合成、3-D は実データ源(Stanford/PDS 等)の DL URL。

• 演算子の来歴・参考文献 — この op 族の元になった研究/手法の出典。

• アルゴリズムの正典(著者・年)と用途は上記ファミリ使い方ガイドに記載。

実行できる例(この op を実際に呼ぶ検証済みサンプル)

• specular_photometric — py -3.11 examples/specular_photometric.py

型が繋がる次の op(rgbimage を入力に取れる)

specular_diffuse_split · specular_coefficient_map · illuminant_from_dichromatic_planes

同カテゴリ(dichromatic)

specular_diffuse_split · specular_coefficient_map · illuminant_from_dichromatic_planes

*Provenance: specularity.py — SPECULAR operator registry. この per-op ノートは tools/opdocs.py md が自動生成(手編集しない)。*

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