fullseye

tb_specular_free_transform — 2D typed op

tb_specular_free_transform: input → output

図は合成の入力 128×128 で実際に走らせた出力。左が入力、右が出力。点群は上から見た散布(明るさ = z)、1-D 列は折れ線、体積は z 方向の最大値投影、動画は中央フレーム、複素画像は振幅、絵にならない返り値は値そのもの。

つまみ a は出力を変えない(実測: 0.1 / 0.5 / 0.9 で同一)。

つまみ b は出力を変えない(実測: 0.1 / 0.5 / 0.9 で同一)。

段階(前置きの op → この op。左から順):

tb_specular_free_transform: stages

別の画像でも(合成シーン / 写真 / 硬貨。上段が入力、下段がその出力。つまみは既定):

tb_specular_free_transform: other inputs

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.

Typed bridge of the specular op specular_free_transform into the 2-D evolution registry: the same implementation, called under the op(v, a, b) convention. This op has no tunable parameter; a and b are unused.

参考(サンプルデータ・文献)

Studio で試す

下のプログラムは実際に走ることを確かめてある(図と同じ入力)。Studio のヘルプではこのブロックがボタンになり、その場で読み込んで実行できる。

img_to_rgb 0.50 0.50
tb_specular_free_transform 0.50 0.50

実行できる例(この op を実際に呼ぶ検証済みサンプル)

次の例は元の台帳 op specular_free_transform を呼ぶもの。この橋渡し op は同じ実装を fn(v, a, b) 規約に合わせただけなので、挙動はそのまま当てはまる(呼び出し形だけ違う)。

型が繋がる次の op(rgbimage を入力に取れる)

identity · tb_wetness · tb_sensor_capture · tb_viewport_from_equirect · tb_specular_diffuse_split · tb_specular_coefficient_map · tb_rgb_to_quaternion

同カテゴリ(typed)

tb_points_to_voxel · tb_estimate_point_normals · tb_iss_keypoints · tb_project_points · tb_render_point_depth · tb_points_render · tb_statistical_outlier_removal · tb_radius_outlier_removal


Provenance: ops.py — 2D 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.