tb_monogenic_orientation — 2D typed op

• 数据种类:qimage → image

• 调用:fullseye.apply(img, "tb_monogenic_orientation", 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])

tb_monogenic_orientation: input → output

*图为在 128×128 合成输入上实际运行的输出。左为输入,右为输出。点云以俯视散点显示(亮度 = z),一维序列为折线,体数据为沿 z 的最大值投影,视频为中间帧,复数图像为幅值;无法成像的返回值直接显示数值。*

*输出以类 viridis 伪彩色显示(深紫 = 小,黄 = 大),便于读取距离、相位、方向、深度这类“量的场”。*

*旋钮 a 不改变输出(实测: 0.1 / 0.5 / 0.9 相同)。*

*旋钮 b 不改变输出(实测: 0.1 / 0.5 / 0.9 相同)。*

阶段(前置算子 → 本算子,从左到右):

▸ tb_monogenic_orientation: 处理阶段 (文档网站)

换别的图像(合成场景 / 照片 / 硬币。上排为输入,下排为对应输出。旋钮取默认):

▸ tb_monogenic_orientation: 其他输入图像 (文档网站)

用法

单演信号的局部方向 atan2(R2, R1)。→ (H, W)。

> 以下的详细说明为原文 —— 摘要与标题已翻译。

Radians in [0, pi): an orientation is defined modulo pi (a grating at 10 degrees and one at 190 degrees are the same grating), and the value is folded into that range rather than left in (-pi, pi] where the same structure would read as two different numbers on either side of a contrast reversal. display=True maps it to [0, 1].

Continuous, not quantised — the angle is read directly from two filters, for any angle, where a steerable bank with K orientations interpolates between its K. Measured against eight grid-exact grating orientations the error is at most 3.6e-15 rad, including the obliques. (Whether that buys anything downstream is a separate question, and the measured answer is mostly *no* — see riesz_displacement.)

Where it is undefined, and the mask is not the one you expect. The orientation dies where the *Riesz vector* dies, which is at every even-symmetric point — local phase 0 or pi, the crest of a bright or dark line — and the amplitude is at full strength there. Measured on a 45-degree grating, the worst orientation error over the whole frame is 0.2764 rad, at a pixel where |R| = 6.8e-16 and monogenic_amplitude reads 1.0000. So masking on the amplitude does not protect you; mask on hypot(q[..., 1], q[..., 2]), the Riesz magnitude. With that mask the error over the same eight orientations is at most 3.6e-15 rad.

Where the Riesz vector is exactly zero, atan2(0, 0) = 0 is returned — a *value*, not a measurement.

Raises ValueError: the input is not a valid quaternion field, or its k component is non-zero; *display* is not a bool.

Typed bridge of the quat op monogenic_orientation into the 2-D evolution registry: the same implementation, called under the op(v, a, b) convention. This op has no tunable parameter; a and b are 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。

在 Studio 中试试

下面的程序已确认可以运行(与图相同的输入)。在 Studio 帮助中,此块会变成按钮,可当场加载并运行。

img_to_monogenic 0.50 0.50
tb_monogenic_orientation 0.50 0.50

▸ 载入此流水线  ·  载入并运行

可运行的示例(实际调用该算子并已验证的样例)

下面的示例调用的是底层账本算子 monogenic_orientation。此桥接算子只是把同一实现适配为 fn(v, a, b) 约定,行为完全相同(只是调用形式不同)。

• quaternion_monogenic — py -3.11 examples/quaternion_monogenic.py

类型可衔接的下一个算子(可接受 image 作为输入)

identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter

同类别(typed)

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


*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.