如何拉直图像中的倾斜方形？ [英] How to straighten a tilted square shape in an image?

问题描述

如何在图像中拉直倾斜的方形？
我不知道它倾斜的角度，代码必须计算它然后自动旋转它。

How can I straighten a tilted square shape in an image? I do not know the angle with which it is tilted and the code must calculate it and then rotate it automatically.

例如，我有以下图像：

应旋转以提供以下输出图像：

which should be rotated to give the following output image:

推荐答案

一种只使用顶角和底角的简单方法。请注意，此方法依赖于上下角：

A simple way using only the top and bottom corners. Note that this approach relies on the upper and lower most corners:

i = imread('sq.jpg');
i_bw = im2bw(i)==0;
% Modify the strel as required
se = strel('square', 10);
i_ed = imopen(i_bw, se);

limits = sum(i_ed, 2);

top_y = find(limits>0, 1);
bottom_y = find(limits>0, 1, 'last');
top_x = round(mean(find(i_ed(top_y, :)>0)));
bottom_x = round(mean(find(i_ed(bottom_y, :)>0)));    

slope = -1 * (top_y - bottom_y)/(top_x - bottom_x);
rot_angle = 2 * pi * atan(slope);

i2 = imrotate(i, -rot_angle);
imshow(i2)

BEFORE
< a href =https://i.stack.imgur.com/Gq8qx.jpg =nofollow noreferrer>

AFTER

这篇关于如何拉直图像中的倾斜方形？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！