fullseye

tb_lf_depth_from_focus — 2D typed op

tb_lf_depth_from_focus: 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。

出力は viridis 風の疑似カラー(暗い紫 = 小、黄 = 大)。距離・位相・向き・深度のような「量の場」を読むため。

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_depth_from_focus: 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_lf_depth_from_focus: other inputs

使い方

Per-pixel slope from the sharpness peak across the refocus sweep.

Refocus at every slope in slopes, measure local sharpness (measure: laplacian = summed modified Laplacian, the classical depth-from-focus operator; variance = local variance; gradient = local gradient energy) in a window x window neighbourhood, and take the slope at which each pixel is sharpest. With subpixel=True (default) the peak is refined by fitting a parabola through the winning sample and its two neighbours on a uniformly spaced sweep — on a non-uniform sweep the refinement is skipped rather than applied with the wrong spacing.

Unbiased where :func:lf_epi_slope is not: measured 2026-09-01 on a 5x5x64x64 synthetic field over a 121-point sweep from -3 to +3, the argmax landed exactly on the true slope in 18 of 18 combinations (true slopes 0.0, +0.5, +1.0, +1.5, +2.0, -1.0 crossed with texture sigma 1.5 / 3.0 / 5.0 px), and the sub-pixel refinement left every one of them unmoved. Its resolution, though, is whatever you put in slopes — it cannot see a plane you never refocused on.

Returns (slope_map, sharpness): the (H, W) map of estimated slopes (in px per angular step) and the (H, W) peak focus-measure value, which is the honest confidence — a textureless pixel has no sharpness peak, gets an essentially arbitrary slope, and its sharpness is ~0. Threshold on it rather than trusting the map everywhere.

Raises ValueError: lf not a valid light field, slopes empty / over :data:MAX_STACK_SLICES / over :data:MAX_STACK_ELEMENTS / containing a non-finite or over-large value, an even or non-positive window, unknown measure / interp / edge.

Typed bridge of the lightfield op lf_depth_from_focus 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_lightfield 0.50 0.50
tb_lf_depth_from_focus 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 lf_depth_from_focus 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(image を入力に取れる)

identity · gaussian · mean_box · mean_box_wh · bilateral · kuwahara · unsharp · median

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.