tb_lf_synthetic_aperture — 2D typed op

• データ種: lightfield → image

• 呼び出し: fullseye.apply(img, "tb_lf_synthetic_aperture", a=0.5, b=0.5) (2-D は 1 画像 + 2 スカラつまみ a,b∈[0,1] のモデル)

tb_lf_synthetic_aperture: 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_lf_synthetic_aperture: 段階の図 (docs サイト)

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_lf_synthetic_aperture: 別の画像での出力 (docs サイト)

使い方

Refocus through a shaped aperture — and, with reduce="median", through occluders.

Same shift-and-add geometry as lf_refocus, with two additions:

• *mask* — a (V, U) weight array from lf_aperture_mask (or your own). A small mask is a stopped-down aperture: less defocus blur, less light. None weights every view equally.

• *reduce* — how the aligned views are combined. mean is the classical (and linear) synthetic aperture. median is the interesting one: when a foreground occluder covers a *minority* of the views at a pixel, the median rejects it and the background behind it is reconstructed — looking through a fence, or through a rack of parts. max / min are the order-statistic extremes, useful for specular / shadow work. median, max and min use the mask only to *select* views (weight > 0), because an order statistic has no meaningful weighting; that is stated here rather than silently ignoring the weights.

The see-through result is not a metaphor. When fewer than half the views are blocked at a hidden pixel, more than half of them carry the identical background sample and the median is that sample exactly. Measured 2026-09-01 on a 9x9x64x64 field with an occluder covering 25% of the centre view at slope 3.0 (blocking at most 46% of the views at any hidden pixel):

RMS against the true, hidden background was 0.0 for median and 0.159 for mean, with the centre view itself at 0.280. Push the coverage to 35% (up to 60% of views blocked) and the guarantee is gone — the median lands at 0.133, worse than nothing.

Returns a (H, W) 2-D image.

Raises ValueError: *lf* not a valid light field, a *mask* whose shape is not (V, U) or which is non-finite / negative / selects no view, a non-finite or over-large *slope*, unknown *reduce* / *interp* / *edge*.

Typed bridge of the lightfield op lf_synthetic_aperture 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)

• 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。

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_lightfield 0.50 0.50
tb_lf_synthetic_aperture 0.50 0.50

▸ このパイプラインを読み込む  ·  読み込んで実行

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 lf_synthetic_aperture 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)。

• lightfield_depth — py -3.11 examples/lightfield_depth.py

• poc_compound_eye — py -3.11 examples/poc_compound_eye.py

型が繋がる次の op(image を入力に取れる)

identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter

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_statistical_outlier_removal · tb_radius_outlier_removal · tb_voxel_grid_downsample


*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.