sinogram_design — TOMOGRAPHY layout op

Datenarten: keinetable (ein Operator, der allein durch seine Argumente bestimmt ist — er nimmt kein Bild und keine Daten entgegen)

Aufruf: import tomography; tomography.sinogram_design(n_angles=180, n_detectors=None, size=256, detector_pitch_mm=1.0, span_deg=180.0) (oder opstomography.get("sinogram_design"))

Verwendung

Was eine Scangeometrie auflösen kann und was nicht — bevor irgendetwas gebaut wird.

> Die ausführliche Beschreibung unten ist der Originaltext — Zusammenfassung und Überschriften sind übersetzt.

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_mm2 * 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_samplingceil(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_px1 / 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.

Referenzen (Beispieldaten, Literatur)

• Katalog der Beispieldaten (Download-URLs / Lizenzen) — 2-D nutzt skimage.data (BSD/Public Domain) plus synthetische Bilder, 3-D nennt Download-URLs echter Datenquellen (Stanford, PDS, …).

• Herkunft und Literatur der Operatoren — die Quellen der Forschung/Verfahren, auf denen diese Operatorfamilie beruht.

• Der kanonische Algorithmus (Autor, Jahr) und seine Anwendungen stehen im Familienleitfaden oben.

Ausführbare Beispiele (verifizierte Samples, die diesen Operator wirklich aufrufen)

ct_reconstructionpy -3.11 examples/ct_reconstruction.py

tomography_reconstructpy -3.11 examples/tomography_reconstruct.py

Typkompatible Folge-Operatoren (nehmen table als Eingabe)

Gleiche Kategorie (layout)

projection_angles


*Provenance: tomography.py — TOMOGRAPHY Operator-Registry. Diese Notiz wird von tools/opdocs.py md erzeugt (nicht von Hand bearbeiten).*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.