tb_mirror_plane_from_pairs — 2D typed op

Data kinds: pointsmatrix

Call: fullseye.apply(img, "tb_mirror_plane_from_pairs", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

tb_mirror_plane_from_pairs: input → output

*The figure is the actual output on a synthetic 128×128 input. Left: input, right: output. Point clouds are drawn as a top-down scatter (brightness = z), 1-D series as a line plot, volumes as the maximum-intensity projection along z, videos as the middle frame, complex images as magnitude; return values that are not pictures are shown as the values themselves.*

*Knob a does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*

*Knob b does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*

Stages (the ops that come before → this op, left to right):

tb_mirror_plane_from_pairs: stages (docs site)

On other images (synthetic scene / photo / coins. Top row: inputs, bottom row: their outputs. Knobs at default):

tb_mirror_plane_from_pairs: other inputs (docs site)

Usage

> This operator's description has not been translated yet. The original text follows as it is.

左右の対応ランドマークから正中面を出す。→ `(2, 3)`(1 行目 = 点、2 行目 = 法線)。

左右の対 `(i, j)` の中点は、どれも正中面の上に乗る。だからその中点集合に

平面を当てればよい —— 変形の量に依らず面が決まるのが要点で、残差を最小に

する面(:func:symmetry3d.detect_reflection_symmetry)とは別物である。

★ 2026-09-06 の実測: 6.4 mm の片側変形を入れると、**残差最適面は真の正中面

から 2.92 mm / 1.72 度ずれ、非対称量の 46 % を消した**(利得 0.54)。この

ランドマーク面なら利得 1.03。見つけるなら残差最適面、量を言うならこちら

*midline* は正中線上にある(対にならない)ランドマークの添字。与えると

中点集合に足して面の当てはめを安定させる。

`pairs=None は**前半と後半を対にする**規約(ii + N//2`)。

左のランドマークを全部並べてから右を同じ順で並べる、という保存形式が

形態計測では一般的なので、それに合わせてある。点数が奇数なら拒否する

—— 半分に割れない並びを黙って切り詰めると、対が 1 つずつずれて全部の

符号が入れ替わる。

2-D 進化レジストリへ橋渡しした shapestat の op `mirror_plane_from_pairs。実装は同じで、呼び出し規約だけ op(v, a, b) に合わせてある。この op に調整点は無く、ab` も使われない。

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.

Try it in Studio

The program below has been verified to run (same input as the figure). In Studio's help this block becomes buttons that load and run it on the spot.

img_to_points 0.50 0.50
tb_mirror_plane_from_pairs 0.50 0.50

▸ Load this pipeline  ·  Load & run

Runnable examples (verified samples that actually call this op)

The examples below call the underlying ledger op mirror_plane_from_pairs. This bridge op is the same implementation adapted to the fn(v, a, b) convention, so the behaviour carries over unchanged (only the call form differs).

shapestat_landmark_tourpy -3.11 examples/shapestat_landmark_tour.py

Ops the type connects to (they accept matrix as input)

identity · tb_mat_pinv · tb_mat_cond · tb_stat_covariance · tb_stat_correlation · matrix_to_img

Same category (typed)

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


*Provenance: ops.py — 2D 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.