tb_lf_refocus — 2D `typed` op

• 数据种类:lightfield → image

• 调用:fullseye.apply(img, "tb_lf_refocus", 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_lf_refocus: 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。*

*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_lf_refocus: stages (docs site)

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_lf_refocus: other inputs (docs site)

用法

位移叠加重聚焦：在指定 *slope* 处对焦的合成孔径图像。

> 以下的详细说明为原文 —— 摘要与标题已翻译。

Every view `(v, u) is shifted by (-s*(v - v_c), -s*(u - u_c))` — the

minus undoes the parallax of a point at slope `s` — and the shifted

views are averaged. Points at that slope add coherently and stay sharp;

everything else is smeared by an amount proportional to its slope

difference times the angular baseline. `slope=0` is the plane the array

was already focused on and returns the plain average of the views.

Ground truth it reproduces exactly (pinned in `tests/test_lightfield.py`):

a single-layer field synthesised at slope `s0 and refocused at s0`

with `edge="wrap" and an integer s0` returns the original texture to

5.6e-16; sweeping the slope, the variance of the result peaks at `s0`

(measured exactly on the sweep grid in all 18 texture/slope combinations

listed in the module docstring), and refocusing at `-s0` does *not* —

which is the check that catches a flipped shift sign.

Returns a `(H, W)` 2-D image.

Raises `ValueError`: *lf* not a valid light field, a non-finite or

over-large *slope* (:data:MAX_ABS_SLOPE), unknown *interp* / *edge*.

Typed bridge of the lightfield op `lf_refocus 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_lightfield 0.50 0.50
tb_lf_refocus 0.50 0.50

▸ Load this pipeline · Load & run

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 lf_refocus。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)。

• lightfield_depth — py -3.11 examples/lightfield_depth.py

• poc_lightfield_depth — py -3.11 examples/poc_lightfield_depth.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)。*

tb_lf_refocus — 2D typed op

用法