layout op• 数据种类:无 → signal(仅由参数决定的算子 —— 不接受图像或数据输入)
• 调用: import fullseye as fs; fs.ledger.projection_angles(n_angles=180, span_deg=180.0, scheme='uniform', start_deg=0.0)(要直接调用实现,import tomography; tomography.projection_angles(n_angles=180, span_deg=180.0, scheme='uniform', start_deg=0.0);从台账取用则 opstomography.get("projection_angles"))
扫描的角度序列,以度为单位的一维 float64 数组。
> 以下的详细说明为原文 —— 摘要与标题已翻译。
Three schemes, and the difference between them is what happens when a scan is cut short:
• "uniform" — start + span * k / n. The textbook scan. A prefix of it covers only a wedge, so an interrupted uniform scan is a limited-angle scan.
• "golden" — increments of 180/phi = 111.246... degrees, wrapped into [start, start+span). Every prefix is near-uniform, so an interrupted golden scan is a *sparse* scan, which is a far easier problem. Largest angular gap left by a scan that stops early, measured:
scheme after 32 of 180 all 180
uniform 149.000 deg 1.000 deg
golden 10.031 deg 1.464 deg
bit-reversed 8.000 deg 1.000 deg
Uniform's 149-degree hole is the entire limited-angle problem arriving by
accident. Bit-reversed is the only one of the three that is good at both
ends; golden's price for working at *every* prefix length rather than only
at powers of two is a completed set 1.46x less even than the grid.
• "bit-reversed" — the uniform grid, visited in bit-reversed order. Same guarantee as golden for power-of-two prefixes and exactly uniform at the end, which golden is not.
*span_deg* is the total angular range. 180 degrees is the complete data set for parallel beam — projections at theta and theta+180 are mirror images and carry no new information — so a 360-degree span is redundancy, not resolution, and anything under 180 is the limited-angle problem.
:param n_angles: number of views, 1 .. 65536. :param span_deg: total angular range in degrees, > 0. :param scheme: one of ANGLE_SCHEMES. :param start_deg: angle of the first view. :returns: (n_angles,) float64 array of degrees. :raises ValueError: on a non-int count, a non-positive span, a non-finite
start, or an unknown scheme.
• 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。
• ct_reconstruction — py -3.11 examples/ct_reconstruction.py
• poc_battery_ct_degradation — py -3.11 examples/poc_battery_ct_degradation.py
• poc_ct_fidelity — py -3.11 examples/poc_ct_fidelity.py
• tomography_reconstruct — py -3.11 examples/tomography_reconstruct.py
signal 作为输入)—
layout)*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.