tb_cplx_cr_residual — 2D typed op

数据种类:cimagefeature

调用:fullseye.apply(img, "tb_cplx_cr_residual", a=0.5, b=0.5)(2-D 的模型是一张图 + 两个标量旋钮 a,b∈[0,1])

*无图: 该算子以 cimage 为输入。从图像开始的 Studio 程序无法到达该类型,请参见下方的可运行示例。*

用法

采样复数场的 Cauchy-Riemann 残差——将“这个场是否全纯?”量化为一个数值。

> 以下的详细说明为原文 —— 摘要与标题已翻译。

With `f = u + i v` sampled on a uniform grid, holomorphy means

`u_x = v_y and u_y = -v_x` (Cauchy-Riemann). This returns the

relative residual `max(|u_x - v_y|, |u_y + v_x|) / max|grad|`

(central differences, `numpy.gradient): 0` = the samples satisfy CR to

the discretisation limit, `2` = the field is the conjugate of a

holomorphic one (`conj(z)` gives exactly 2), values in between = partly

analytic or noisy.

Grid convention (it decides the sign of the answer): `f[i, j]` is the

field at `z = x0 + j*spacing + i*spacing*1j` — rows index the *increasing

imaginary* axis, columns the real axis. Image arrays usually run rows

*downward*; feeding one directly measures the conjugate field, whose

residual is `2, not 0. Flip rows (f[::-1]`) to use image data.

Discretisation, honestly: central differences are exact for polynomials of

degree <= 2, so `f = z**2` returns exactly 0; for higher order the

residual floors at `O(h^2 * |f'''|) (measured: f = z**3` on a

`[-1,1]^2 grid returns 1.7e-3 at h` and 4.2e-4 at

`h/2` — a factor 4.00, the expected second order). Read a

small value as "consistent with holomorphic at this resolution", never as

proof.

A constant field returns `0.0 (it is holomorphic; the 0/0` of the

normalisation is resolved by that limit, and stated here rather than left

to numpy).

Raises `ValueError`: not a 2-D array, either dimension below 3 (no

central difference exists), non-finite/masked input, over-cap size,

non-finite or non-positive *spacing*.

HALCON: no operator (`derivate_gauss` supplies the real-valued

derivatives one would build this from).

Typed bridge of the math op `cplx_cr_residual into the 2-D evolution registry: the same implementation, called under the op(v, a, b) convention. a drives spacing (default 1); b` is unused.

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。

可运行的示例(实际调用该算子并已验证的样例)

• (暂无)

类型可衔接的下一个算子(可接受 feature 作为输入)

identity

同类别(typed)

tb_points_to_voxel · tb_estimate_point_normals · tb_iss_keypoints · tb_angle_3points · tb_project_points · tb_render_point_depth · tb_statistical_outlier_removal · tb_radius_outlier_removal


*Provenance: ops.py — 2D 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.