lens_shading_gain — GFX2D isp op

• データ種: image2d → image2d

• 呼び出し: import fullseye as fs; fs.ledger.lens_shading_gain(flat, pattern=None, smooth_sigma=0.0) (実装を直接呼ぶなら import gfx2d; gfx2d.lens_shading_gain(flat, pattern=None, smooth_sigma=0.0)、台帳から引くなら opsgfx2d.get("lens_shading_gain"))

使い方

The gain map that flattens a flat-field frame: `gain = mean / flat`

per colour channel (or for the whole frame when *pattern* is `None`).

Shoot a uniform white target; vignetting and the micro-lens fall-off make

the corners darker. Multiplying any later frame by this map undoes that.

*smooth_sigma* > 0 Gaussian-smooths the flat first (per channel) so sensor

noise and dust do not become gain speckle. The gain is normalised so the

channel mean stays 1 — the map corrects shape, not exposure.

Ground truth: `lens_shading_correct(flat, lens_shading_gain(flat))` is a

constant frame (each channel equal to its own mean) to 1e-12.

Raises `ValueError`: non-finite input, a zero or negative pixel in

the flat (no gain can be defined there), or a negative *smooth_sigma*.

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)

• raw_to_display_isp — py -3.11 examples/raw_to_display_isp.py

型が繋がる次の op(image2d を入力に取れる)

shadow_cast_2d · dither · raw_black_level · raw_dead_pixel_mask · raw_dead_pixel_correct · lens_shading_correct · raw_apply_gains · raw_demosaic_bilinear

同カテゴリ(isp)

raw_black_level · raw_dead_pixel_mask · raw_dead_pixel_correct · lens_shading_correct · awb_gains · rgb_apply_gains · raw_apply_gains · raw_demosaic_bilinear

*Provenance: gfx2d.py — GFX2D 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.