如何从图像中提取非零值？

i want to extract lines from a text document. I can accomplish this by summing its columns and produce a 1 dimensional vector (This will be the horizontal projection of the image). This is the image

我想从文本文档中提取行。我可以通过对其列求和并生成一维向量来实现这一点（这将是图像的水平投影）。这是图像

img = imcomplement(rgb2gray(imread('french.jpg')));
lines = sum(img, 2);
plot(lines);

If I plot this I can see that the zero values show the blank spaces and the peaks depict the lines. Here is the plot

如果我绘制这个，我可以看到零值显示空白，峰值描绘了线条。这是情节

So looking at the plot (and the array) I can tell that the third line is from array index 129:184. So to extract it I did this

所以看一下情节（和数组），我可以看出第三行来自数组索引129：184。所以提取它我做了这个

test = lines(129:184);

It does not seem to work as if I do imshow(test) or imshow(test, []) It gives the following result. Not exactly the third line.

它似乎没有像我做imshow（测试）或imshow（test，[]）那样工作。它给出了以下结果。不完全是第三行。

What am I doing wrong here?

我在这做错了什么？

1 个解决方案

#1

You want to display the 2D image rather than 1D line:

您想要显示2D图像而不是1D行：

imshow(img(129:184,:)) 

gives you line 129 - 184.

给你129-184行。