sinogram_center_shift — TOMOGRAPHY geometry op

• 数据种类:sinogram → sinogram

• 调用:import tomography; tomography.sinogram_center_shift(sinogram, shift_px=None, angles_deg=None)(或 opstomography.get("sinogram_center_shift"))

用法

把正弦图重新对中到它的旋转轴上。

> 以下的详细说明为原文 —— 摘要与标题已翻译。

Shifts every projection by `-shift_px` along the detector axis with linear

interpolation. With `shift_px=None` the shift is measured first by

:func:sinogram_center_of_rotation, which makes this the one-call fix.

Round-trip on the Shepp-Logan phantom, shifting by *d* and back:

d max |error| relative to the peak line integral

1.00 px 0.0e+00 0.0e+00 (an integer shift is exact)

0.50 px 1.4e-01 1.2e-01

0.25 px 1.1e-01 9.2e-02

A *fractional* shift is not a small operation and this is the operator's

honest limitation: 12 % of the peak, on a phantom with sharp edges, from one

round trip. Interpolation is a low-pass filter and the sinogram of an edge is

not band-limited, so there is nothing to recover on the way back. Using a

Fourier shift instead would trade this visible blur for invisible ringing at

the detector edges, which is worse in the way that matters here. The

consequence is in :func:sinogram_center_of_rotation's table: an integer

centre error is fully repairable, a half-pixel one is not.

:param sinogram: `(n_angles, n_detectors)`.

:param shift_px: axis offset in detector bins; `None` -> measure it.

:param angles_deg: view angles, used only when *shift_px* is `None`.

:returns: `(n_angles, n_detectors)` float64 sinogram.

:raises ValueError: if `|shift_px|` is at or past half the detector width —

past that the object has been shifted out of the field of view and what

comes back is edge padding, which reconstructs as a plausible, empty slice.

参考(示例数据・文献)

• 示例数据目录(下载 URL / 许可证) —— 2-D 用 skimage.data(BSD/公有领域)加合成图,3-D 给出真实数据源(Stanford/PDS 等)的下载 URL。

• 算子来历与参考文献 —— 该算子族所依据的研究/方法出处。

• 算法的正典(作者・年份)与用途见上面的族使用指南。

可运行的示例(实际调用该算子并已验证的样例)

• ct_reconstruction — py -3.11 examples/ct_reconstruction.py

类型可衔接的下一个算子(可接受 sinogram 作为输入)

backproject_sinogram · filtered_backprojection · sart_reconstruct · beam_hardening_apply · beam_hardening_correct · ring_artifact_apply · ring_artifact_remove · metal_trace_interpolate

同类别(geometry)

sinogram_center_of_rotation

*Provenance: tomography.py — TOMOGRAPHY 算子登记表。本条目由 tools/opdocs.py md 自动生成(请勿手工编辑)。*

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