fullseye

csi_contrast_map — INTERFEROMETRY surface op

• データ種: zscan → image2d
• 呼び出し: import fullseye as fs; fs.ledger.csi_contrast_map(stack, remove_bias=True) (実装を直接呼ぶなら import interferometry; interferometry.csi_contrast_map(stack, remove_bias=True)、台帳から引くなら opsinterferometry.get("csi_contrast_map"))

使い方

Peak fringe modulation per pixel — the contrast (and validity) map.

The maximum of each pixel’s coherence envelope. Three uses, in order of how often they matter:

1. Validity. A pixel that never produced fringes — a hole, a steeply tilted facet that threw the light out of the aperture, a saturated or dark pixel — has near-zero modulation. This is the map you threshold to decide which heights from :func:csi_height_map to trust.
2. Reflectance. In the forward model the envelope peak is exactly amplitude * reflectivity, so with a known amplitude this map is the reflectivity. Verified in the tests: a known reflectivity map over a 5.0-7.0 um surface is recovered with a maximum error of 7.32e-05 (the residual is envelope truncation again — the same surface spread over 2.0-10.0 um gives 4.03e-04). It is a contrast map, not a photometric measurement, and it is accurate to about four decimal places, not to machine precision.
3. Focus. It is the interferometric analogue of a focus measure, and it peaks where :func:csi_height_map says the surface is.

Why use 1 rather than trust the height map everywhere: measured on a flat surface at 6.0 um with a 50x reflectance step across the field (0.02 on one half, 1.0 on the other) and 1 % noise, the "gaussian" height error is 0.146 um RMS on the bright half and 3.03 um RMS on the dark half, and 30 % of the dark pixels are refused outright. The bias barely moves (+0.14 um); what explodes is the scatter, because the three-point fit is reading three samples out of a noise floor. "centroid" degrades far more gracefully on the same data (0.022 -> 0.157 um, 7x rather than 20x), which is the second place in this module where the estimator ranking depends on the data rather than on the algebra. This map is what separates the two populations: it reads 0.035 +- 0.004 on the dark half and 0.412 +- 0.007 on the bright one.

It is deliberately not normalised by the pedestal. The classical fringe visibility is b/a, and computing it would need the pedestal, which remove_bias has just thrown away; returning b and saying so is honest, whereas returning b and calling it visibility would not be. Divide by :func:numpy.mean of the stack along axis 0 if you want the ratio.

Returns a float64 (H, W) map. Same shape and validation as :func:csi_height_map.

Raises ValueError: a non-3-D stack, fewer than 3 planes, an empty spatial extent, a stack over :data:MAX_STACK_ELEMENTS, a non-finite / complex / masked stack, or a non-bool remove_bias.

詳しい使い方ガイド

• coherence_scanning 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)

• coherence_scanning — py -3.11 examples/coherence_scanning.py

型が繋がる次の op(image2d を入力に取れる)

—

同カテゴリ(surface)

csi_height_map

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Provenance: interferometry.py — INTERFEROMETRY 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.

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