How to calculate the curvature of a boundaries in binary images?
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Dear all,
I have a binary image that contains one shape as I show below:
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/146222/image.png)
I want to represent the curvature using color coding of the boundariessimilar to image I got from the video in this link http://en.wikipedia.org/wiki/Curvature
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/146223/image.png)
Does anyone knows how to do that?
Any help or suggestion will be appreciated.
Meshoo
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采纳的回答
Image Analyst
2014-11-27
Use bwboundaries to get a list of the (x,y) boundary coordinates. Run around that border taking a section of the curve, say 9 elements, and fit a polynomial to it. Knowing the derivative of the curve model you used, and the coefficients polyfit() gave you, you can get the curvature at each point. Then run around the list of (x,y) edge coordinates using a marker color that corresponds to the curvature. Try to program that up. If you can't do it all , then post what you have and I'll try to help with the rest.
19 个评论
Francesco Pignatelli
2022-12-9
@Image Analyst I have followed this post and I saw your comments and you mentioned that "Knowing the derivative of the curve model you used, and the coefficients polyfit() gave you, you can get the curvature at each point.". My question is, how is it possible to get the derivatives?
At the current stage, I am at:
boundaries = bwboundaries(binaryImage);
x = boundaries{1}(:, 2);
y = boundaries{1}(:, 1);
So I have x and y now.
Image Analyst
2022-12-10
@Francesco Pignatelli see attached demo that does what I said. Adapt as needed. If you need more help, start your own discussion thread and attach your (x,y) data.
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/1226527/image.png)
更多回答(3 个)
Preetham Manjunatha
2021-8-2
编辑:Preetham Manjunatha
2021-8-4
Here this function measures the curvature and other shape properties. In addition, it displays the curvature.
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/703222/image.png)
Here is the T-section with sharp corners:
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/703227/image.png)
0 个评论
Very nice. Have you worked in gray image the this code ? Have you tried?
Linda Cummings
cummingslinda14 at gmail.com
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sana3 sal
2018-6-18
Hello Mr @Image Analyst, I am wondering how to read the curvature? or how to analyse it?
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/189314/image.jpeg)
3 个评论
Image Analyst
2020-4-9
cyril grandjean
2020-4-10
Hello I read the code well but I was not sure that I understood correctly. So the coefficient provided in this code corresponds to the overall curvature of my form or a trend is that right?
thank you in advance
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