os_sart_reconstruct — TOMOGRAPHY ct_scan op

• 数据种类:projstack × ctgeometry → voxel

• 调用: import fullseye as fs; fs.ledger.os_sart_reconstruct(projections, geometry, n_iter=10, n_subsets=16, relaxation=0.8, initial=None, nonnegative=True, device='auto', on_iter=None)(要直接调用实现,import ctscan; ctscan.os_sart_reconstruct(projections, geometry, n_iter=10, n_subsets=16, relaxation=0.8, initial=None, nonnegative=True, device='auto', on_iter=None);从台账取用则 opstomography.get("os_sart_reconstruct"))

• GPU:无(仅 CPU 参考实现)

用法

OS-SART:将 SIRT 更新逐个应用于有序视角子集。

> 以下的详细说明为原文 —— 摘要与标题已翻译。

One iteration passes over all subsets, so it costs about one SIRT iteration and moves about *n_subsets* times as far early on. With inconsistent data it settles into a limit cycle rather than a point.

:param projections: (view, V, U) line integrals. :param geometry: dict from ct_scan_geometry. :param n_iter: passes over all subsets, 1 .. 5000. :param n_subsets: subsets, 1 .. n_views. :param relaxation: step lam, (0, 2). :param initial: starting volume; None gives zeros. :param nonnegative: clip to >= 0 after each subset. :param device: "auto", "cpu" or "cuda". :param on_iter: optional on_iter(iteration, volume), called after each full

pass; returning a boolean True (bool or numpy.bool_) stops

there, any other return value is ignored.

:returns: (Z, Y, X) float volume. :raises ValueError: on a shape that disagrees with the geometry, a relaxation

outside (0, 2), or more subsets than views. Empty input (projections

with 0 elements) raises ValueError.

The default 10 passes is not converged. On consistent data (24^3 Shepp-Logan, cone, 20 views, 16 subsets) the relative residual is 0.0135 at 10 passes and 0.0044 at 40, nRMS to the truth 0.0278 -> 0.0176 (37 %); on the measured walnut (fan, 50 views, 10 subsets) the RMSE to the reference is 0.0048 /mm at 10 passes and 0.0036 at 40 (2026-11-09 audit). Pick the count from a curve (on_iter, see sirt_reconstruct).

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_scan_modes — py -3.11 examples/ct_scan_modes.py

• poc_ct_casting_sparse_views — py -3.11 examples/poc_ct_casting_sparse_views.py

• poc_real_walnut_cbct — py -3.11 examples/poc_real_walnut_cbct.py

类型可衔接的下一个算子(可接受 voxel 作为输入)

radon_volume · ct_forward_project

同类别(ct_scan)

ct_scan_geometry · shepp_logan_3d · ellipsoid_phantom · ellipsoid_projections · ct_forward_project · ct_adjoint_project · fdk_reconstruct · sirt_reconstruct


*Provenance: ctscan.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.