A fast thinning algorithm

Question

I'm looking for a fast thinning algorithm that can be readily implemented using OpenCV. The mention of the library is because there are certain things that can be done in a jiffy in say, Mathematica or MATLAB which would require lines of handcode in OpenCV+C.

The algorithm must satisfy the 1 pixel thickness and connectedness criteria.

Has anyone got any experience in implementing one of the tons of available algorithms out there? - Literally spoilt for choice at the sheer number of papers Google threw up. Any pointers in the right direction would do.

"has anyone got any experience" type questions tend not to be well answered: do you have a more specific question? — James, Nov 10 '11 at 16:36
@Autopulated: that's true however i *am* asking something a bit vague - there are quite a few fast thinning algorithms, the question is has anyone implemented any using OpenCV and C/C++? — AruniRC, Nov 11 '11 at 15:04
Hello @AruniRC, do you finally get some satisfactory implementation? — zhy, Dec 30 '15 at 06:31

score 23 · Accepted Answer · edited Apr 22 '16 at 17:46

23

Please check some thinning implementations in my blog:

Both using OpenCV 2.x API.

edited Apr 22 '16 at 17:46

Dan Mašek

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answered Jan 14 '13 at 05:01

flowfree

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finally. i ended up using Zhang-Suen, but nice answer. – AruniRC Jan 14 '13 at 13:44
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You should know that your implementation in the post is buggy. It will address outside of the image along the far edges. – Emily L. Jun 15 '15 at 17:15
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@flowfree why your blog is down. it was a good reference page. – sturkmen Apr 22 '16 at 21:32

score 11 · Answer 2 · edited May 23 '17 at 12:25

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for the sake of completeness, I'm posting here a set of thinning algorithms implemented using OpenCV and C/C++ that I found out on the net while answering this question. These have adequately answered this question for my needs. Putting them here in case others have similar requirements.

OpenCV code for thinning (Guo and Hall algo, works with CvMat inputs)
The JR Parker implementation using OpenCV
Possibly more efficient code here (uses OpenCV optimized access methods a lot, however most of the page is in Japanese!)

edited May 23 '17 at 12:25

Community

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answered Jun 04 '12 at 06:22

AruniRC

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Acctually, the 3rd one runs really slower than the two of @flowfree 's answer – zhy Dec 30 '15 at 06:27

score 5 · Answer 3 · answered Oct 29 '13 at 14:33

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I used Zhang-Suen as well Guo-Hall; both produced satisfactory results but not the best ones. Then I tried "A Modified Parallel Thinning Algorithm" by Y. Y. ZHANG and P.S.P Wang. It was far better than the previous two algorithms. Anyone looking for a good thinning algorithm should try it since it is faster and more effective than the other two.

answered Oct 29 '13 at 14:33

marc1886

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did you find any implementation or article explaining this modification? Can you elaborate around how much faster it is? – pzo Jan 16 '14 at 22:42
If you download the research papers and read through them, you will notice that the Zhang-Wang method does only one iteration and additionally, it has some different conditions to be checked. I processed binary images of size 1600 * 1200. It took approx. 5 sec for Zhang-Suen and approx. 3 sec for Zhang-Wang method. – marc1886 Feb 11 '14 at 14:26
Hi Vikramjit, can you share the implementation or describe how you combined the last two conditions? I read the paper but wasn’t sure how to combine the conditions p11=1, p6=0, with conditions p8=0, p15=1 for the modified thinning algorithm. – abe Jun 19 '17 at 01:01

score 1 · Answer 4 · answered Nov 10 '11 at 16:37

Not sure if this will help you, but I've used this library and found it very useful, (which includes thinning/skeletonisation). You can download the source here:

http://www.aforgenet.com/framework/

and a good article of its use here:

http://www.codeproject.com/KB/GDI-plus/Image_Processing_Lab.aspx

A fast thinning algorithm

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