fullseye

sinogram_design — TOMOGRAPHY layout op

• データ種: なし → table(引数だけで決まる op —— 画像やデータの入力を取らない)
• 呼び出し: import fullseye as fs; fs.ledger.sinogram_design(n_angles=180, n_detectors=None, size=256, detector_pitch_mm=1.0, span_deg=180.0) (実装を直接呼ぶなら import tomography; tomography.sinogram_design(n_angles=180, n_detectors=None, size=256, detector_pitch_mm=1.0, span_deg=180.0)、台帳から引くなら opstomography.get("sinogram_design"))

使い方

What a scan geometry can and cannot resolve — before anything is built.

The axial counterpart of :func:visiondesign.imaging_budget and of :func:interferometry.csi_design: no data goes in, only the geometry, and what comes out are the limits that the geometry has already decided.

Returns a dict with, among others:

• resolvable_feature_mm — 2 * pitch: two detector samples per cycle is the Nyquist floor, and no reconstruction algorithm recovers a detail finer than the detector saw.
• views_for_full_sampling — ceil(pi/2 * n_detectors), the classical matching of angular to radial sampling (:data:VIEWS_PER_DETECTOR).
• undersampling_factor — that number over n_angles. 1.0 or below is a fully sampled scan. Above it you are doing sparse-view CT on purpose and the reconstruction algorithm has to make up the difference; the measured cost is in this module’s docstring and in the test suite’s break table.
• streak_free_radius_px — 1 / d(theta) with d(theta) in radians: the radius, in pixels, at which the azimuthal sample spacing between neighbouring views (r * d(theta)) grows past one sample. Outside it, filtered back-projection lays down visible streaks. For 180 views over 180 degrees this is 57.3 px, i.e. a 256-px phantom is already streaking at its corners. It does not depend on the detector pitch: the radius is quoted in the same unit the sample spacing is, so the pitch cancels (pitch / d(theta) is the same radius in millimetres, which is what an earlier version returned under the pixel label — 28.6 “px” at 0.5 mm, 114.6 at 2 mm, for a geometry whose streak radius had not changed).
• sinogram_bytes / elements — what you are about to allocate.
• verdict — "fully sampled" / "sparse view".

:param n_angles: planned number of views. :param n_detectors: planned detector bins; None -> enough to cover the diagonal of a size x size image. :param size: reconstruction grid side in pixels. :param detector_pitch_mm: physical detector bin spacing. :param span_deg: angular range of the scan. :returns: dict of floats / ints / str. :raises ValueError: on non-int counts, non-positive pitch or span.

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)

• ct_reconstruction — py -3.11 examples/ct_reconstruction.py
• tomography_reconstruct — py -3.11 examples/tomography_reconstruct.py

型が繋がる次の op(table を入力に取れる)

—

同カテゴリ(layout)

projection_angles

---

Provenance: tomography.py — TOMOGRAPHY 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.

This site is open source. Improve this page.