subimage with different size

[betty1978]

hello,
i have a problem and i can't find a solution. I created a marker, and i want to search this marker on a Pictue. I think the Problem is the different size from the marker in my image or i need another marker for ImageMagick.

This is the created marker:


And this is my Picture:


I convert the image with follow Command:

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convert original1.png -colorspace Gray -negate -edge 1 -negate original.png

The result is this image:


Now i search the marker with this Command:

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compare -metric rmse -subimage-search original.png maske.png result.png

17735.4 (0.270625) @ 234,198



This position is wrong, and i make a new Image with this Command

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convert original1.png -fuzz 20% -fill black -opaque "#3b3b38" -fuzz 20% -fill white -opaque "#989692" test.png

The result is:

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compare -metric rmse -subimage-search test.png maske.png result1.png

17861.8 (0.272554) @ 230,87



The same Problem, now is the position on top from my marker.
Has anyone any idea what can i do?

[snibgo]

I think the Problem is the different size from the marker in my image ...

Yes, that is the main problem. IM won't automatically resize images to search for a match. If you place one image over the other, you can see that if one corner mark lines up, the others won't.

One trick is to look for small distinctive features. The diagonal cross is distinctive. So crop to that, and then search:

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convert maske.png -gravity center -crop 50%%x50%%+0+0 m.png

compare -metric rmse -subimage-search original.png m.png result.png

The result is then correct.