tb_cplx_cr_residual — 2D typed op

資料種類:cimagefeature

呼叫:fullseye.apply(img, "tb_cplx_cr_residual", a=0.5, b=0.5)(2-D 的模型是一張圖 + 兩個純量旋鈕 a,b∈[0,1])

*無圖: 該運算子以 cimage 為輸入。從影像開始的 Studio 程式無法到達該型別,請參見下方的可執行範例。*

用法

取樣複數場的 Cauchy-Riemann 殘差——把「這個場是否全純?」量化成一個數值。

> 以下的詳細說明為原文 —— 摘要與標題已翻譯。

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.

參考(範例資料・文獻)

• 範例資料目錄(下載 URL / 授權) —— 2-D 用 skimage.data(BSD/公有領域)加合成圖,3-D 給出真實資料源(Stanford/PDS 等)的下載 URL。

• 運算子來歷與參考文獻 —— 該運算子族所依據的研究/方法出處。

可執行的範例(實際呼叫該運算子並已驗證的樣例)

• (尚無)

型別可銜接的下一個運算子(可接受 feature 作為輸入)

identity

同類別(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 運算子登記表。本條目由 tools/opdocs.py md 自動產生(請勿手動編輯)。*

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