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Circle Detection

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Circle Detection

Postby Pavinkumar » Fri Aug 17, 2018 11:01 am


How to detect a circular shape in an binary image when the circle is partially covered / disturbed by some other blobs. Erosion / Dilatation might help a bit, but, I don't want to compromise the full circular area that's been covered in the raw image.

Please check the attached images for reference.

Any help on this would be appreciated !

Raw_Image_3.PNG (5.56 KiB) Viewed 11237 times
Raw_Image_2.PNG (5.96 KiB) Viewed 11237 times
Raw_Image_1.PNG (2.92 KiB) Viewed 11237 times
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Re: Circle Detection

Postby andrew.kirillov » Mon Aug 20, 2018 6:57 am


One thing to try is edge detection and then Hough Circle Transformation. But you need to know radius of the circle you want to detect.
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Re: Circle Detection

Postby Pavinkumar » Thu Aug 23, 2018 2:09 pm


Thanks for the suggestion. It did work out for me. I did Canny Edge Detection & then Hough Circle Transform.

The exact radius of the circle is unknown for me. But, I know an approximate range [ex : 20 to 60]. I did the same procedure for all the possible values in the range & then filtered out the one with maximum Intensity. This did work out for me to locate the circle i am looking for. This even helped me filter out the biggest circle if there are multiple circles in the given image.

Thank you again :)
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