decomposition op• Data kinds: image → image
• Call: fullseye.apply(img, "dc_structure_texture", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
*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.*
*The output is shown in a viridis-like pseudo-colour (dark purple = low, yellow = high) so that a field of quantities — distance, phase, orientation, depth — can be read.*
Sweeping knob a (0.1 / 0.5 / 0.9, the other knob at its default):
▸ dc_structure_texture: knob a sweep (docs site)
*Knob b does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*
On other images (synthetic scene / photo / coins. Top row: inputs, bottom row: their outputs. Knobs at default):
▸ dc_structure_texture: other inputs (docs site)
*The 4th column is a colour (H,W,3) input. This op handles colour without crossing channels (it does not convolve the colour channel as a third spatial axis).*
Structure / cartoon part of the image (TV-L2, Chambolle).
> The detailed description below is the original text — the summary and the headings are translated.
画像を「構造(cartoon)+テクスチャ」に分け、構造側を返す。ROF/TV-L2 モデル
`min_u ||u - f||^2 / (2*weight) + TV(u)` を Chambolle(2004)の双対射影法で
固定 120 反復(`tau=0.125)解く。weight = 0.02 + 0.28*a で、a` が
大きいほど滑らか(平坦な区画が広がり、細かい模様が消える)、`a=0` でも
ごく弱い平滑が入る。`b` は未使用。
入力は 2 次元 float64・[0,1] に揃える(3 次元はチャネル平均、NaN→0、
±Inf→1/0)。返り値は入力と同形の float64、[0,1] に clip。飽和しない限り
`dc_structure_texture + (dc_texture_residual - 0.5) == 入力` が成り立つ。
1xN / Nx1 など 2 次元の発散が定義できない極小画像は入力をそのまま返す
(構造=入力、テクスチャ=0.5)。例外時は fail-soft で入力のクリップ版が返り、
backend_safe の台帳に記録される(strict モードでは再送出)。
ガウスぼかしと違ってエッジ(段差)は保ち、模様・ノイズだけを落とす。反復数が
固定なので大きな画像では収束しきらないことがある(残りはテクスチャ側に出る)。
テクスチャ側だけが欲しければ `dc_texture_residual`。周期模様の除去や
欠陥検出の前処理として使い、後段に `threshold や dyn_threshold`。
背景が低ランク(縞・グラデーション)なら `dc_rpca_lowrank` も候補。
• gallery2d_texture_freq family guide
• blas_threads_and_memory — 行列分解が遅い理由の知識 — BLAS スレッド・キャッシュ・メモリ配置
• 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.
• The canonical algorithm (author, year) and its uses are named in the family usage guide above.
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.
dc_structure_texture 0.50 0.50
▸ Load this pipeline · Load & run
• gallery2d_texture_freq — py -3.11 examples/gallery2d_texture_freq.py
• poc_fiber_orientation — py -3.11 examples/poc_fiber_orientation.py
image as input)identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter
decomposition)dc_texture_residual · dc_rpca_lowrank · dc_rpca_sparse · dc_retinex · dc_local_contrast_norm · dc_homomorphic
*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.