如何使用linux控制台搜索图像的子图像？ [英] How to search an image for subimages using linux console?

问题描述

我必须使用控制台搜索较大图像中较小图像的出现。结果我想收到它的图像坐标。可能有哪些解决方案？

I have to search for the occurrence of a smaller image in a larger one using the console. As result I want to receive it`s image coordinates. What solutions are possible?

我听说过ImageMagick，但不太了解它是如何工作的。如果它足够了，那么我会很感激一个示例命令。

I heard about ImageMagick, but not really understand how it works. If it`s enough, then I would appreciate an example command.

谢谢。

推荐答案

这是一个小例子，你可以看看它是如何工作的......

Here's a little example so you can see how it works...

首先，我们的针图像

现在制作干草堆，绿色和蓝色 - 非常时尚： - ）

Now make a haystack, green and blue - very stylish :-)

convert -size 256x256 gradient:lime-blue haystack.png

现在在大海捞针中隐藏两根针，一次一根，没什么好看的：

Now hide two needles in the haystack, one at a time, nothing fancy:

convert haystack.png needle.png -geometry +30+5 -composite haystack.png 
convert haystack.png needle.png -geometry +100+150 -composite haystack.png 

现在搜索大海捞针，将生成两个输出文件， locations-0.png 和位置-1.png

Now search for the needles in the haystack, two output files will be produced, locations-0.png and locations-1.png

compare -metric RMSE -subimage-search haystack.png needle.png locations.png > /dev/null 2>&1

这是第二个更有用的输出文件位置-1.png 。它是黑色的，其中IM确定没有匹配并逐渐接近白色，更确定的ImageMagick是匹配。

This is the second, more useful output file locations-1.png. It is black where IM is sure there is no match and progressively nearer to white the more certain ImageMagick is that there is a match.

现在查找IM为95 +％的位置确定匹配并将所有像素转换为文本，以便我们搜索单词白色。

Now look for locations where IM is 95+% certain there is a match and convert all pixels to text so we can search for the word white.

convert locations-1.png -threshold 95% txt: | grep white

输出就是这个，这意味着ImageMagick发现了30,5和100,150的针 - 确切地说我们藏在哪里！告诉你它是魔法！

The output is this, meaning ImageMagick has found the needles at 30,5 and 100,150 - exactly where we hid them! Told you it was Magic!

30,5: (255,255,255)  #FFFFFF  white
100,150: (255,255,255)  #FFFFFF  white

这是整个脚本，因此您可以运行它并播放有了它：

Here is the entire script so you can run it and play with it:

#!/bin/bash
convert -size 256x256 gradient:lime-blue haystack.png                      # make our haystack
convert haystack.png needle.png -geometry +30+5 -composite haystack.png    # hide our needle near top-left
convert haystack.png needle.png -geometry +100+150 -composite haystack.png # hide a second needle lower down

# Now search for the needles in the haystack...
# ... two output files will be produced, "locations-0.png" and "locations-1.png"
compare -metric RMSE -subimage-search haystack.png needle.png locations.png > /dev/null 2>&1

# Now look for locations where IM is 95% certain there is a match
convert locations-1.png -threshold 95% txt: | grep white

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