python-3.x - 为什么 HoughLinesP 输出 3D 数组，而不是 2D 数组？

Question

我正在对图像使用函数(Python、Numpy、OpenCV3)，这是我的示例输出 -

[[[539 340 897 538]]

 [[533 340 877 538]]

 [[280 460 346 410]]

 [[292 462 353 411]]

 [[540 343 798 492]]]

它的大小是(5,1,4)

我试图了解该函数在什么情况下会输出类似 (5,2,4) 或 (5,3,4) 的内容。但我现在想不起我使用过的任何图像，它是一个列数为 1 的 3D 数组。

仅仅一个 2D 数组就足够了，而且可能更高效吗？

Answer 1

我询问了 OpenCV 问答并得到了以下答复 -

opencv is a c++ library, and the python wrappers are auto-generated from some scripts, so in c++ we have:

vector lines; to hold the hough results.

now unfortunately , Vec4i is a descendant of Matx , which is actually a 2d thing, so in python you get:

[ #one for the vector

[ #one for the 1st dim of Vec4i (1, pretty useless, admittedly :)

[ #one for the 2nd dim of Vec4i (4 elements)

again, i think, you'll just have to live with it.