fullseye

photometric_residual — SPECULAR `photometric` op

データ種: images → image2d
呼び出し: import fullseye as fs; fs.ledger.photometric_residual(images, lights, normals=None, albedo=None, normalize=True) (実装を直接呼ぶなら import specularity; specularity.photometric_residual(images, lights, normals=None, albedo=None, normalize=True)、台帳から引くなら opsspecular.get("photometric_residual"))

使い方

How badly the Lambertian model fails, per pixel. → (H, W) RMS residual.

sqrt(mean_n (albedo * (n.L_n) - I_n)^2) — the root-mean-square disagreement between the linear model and the measurements, in the units of the input radiance. On a synthetic Lambertian surface with the true float64 normals and albedo supplied it measures 1.4e-16 at worst; with them omitted the floor rises to 4.5e-08, because :func:photometric.photometric_stereo returns float32 and that is its precision, not a modelling error (supplying the same truth cast to float32 reproduces 4.5e-08 exactly). It is large where the assumption actually broke: 0.50 at worst on the same scene with 3 of 8 lights blocked by a cast shadow — fifteen orders of magnitude above the clean floor. All four numbers measured in tests/test_specularity.py.

This is the diagnostic that tells you whether you need :func:photometric_stereo_robust before you reach for it, and it is the map an inspection routine thresholds to find glossy defects.

With normals and albedo omitted it solves them first with :func:photometric.photometric_stereo and reports the residual of that fit — the honest self-assessment of the plain estimator. Pass them to score an estimate that came from somewhere else (a robust fit, a CAD model, a previous frame).

Note the residual uses n.L without the max(., 0) clamp, because that is the linear system the solver actually inverted; a pixel in attached shadow therefore shows a residual, which is the intended signal rather than an artefact.

Raises ValueError: images / lights problems as in :func:photometric_stereo_robust; normals is not (H, W, 3) matching the images; albedo is not (H, W); exactly one of normals / albedo is given (the pair is meaningless apart — the model is albedo * n).

詳しい使い方ガイド

specular_photometric ファミリガイド

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。
アルゴリズムの正典(著者・年)と用途は上記ファミリ使い方ガイドに記載。

実行できる例(この op を実際に呼ぶ検証済みサンプル)

specular_photometric — py -3.11 examples/specular_photometric.py

型が繋がる次の op(`image2d` を入力に取れる)

polarization_render

同カテゴリ(`photometric`)

photometric_stereo_robust

Provenance: specularity.py — SPECULAR 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)。

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