Circle detect in an image

marco73it

I am interested in circle detection on an image. I have used the Blobdetection library, however this code does not work correctly if many circles are present and merge togheter (many circles merged togheter are counted as a single blob). I have read about the Hough Circle function of Opencv. However I have not understood how this function can be used in processing once the opencv library is imported (the code I found on the web does not work in processing). Anyone can help? Thanks.

jeremydouglass

You said:

many circles merged together are counted as a single blob

Can you explain this part very specifically? Do you mean you are trying to detect two circles in shapes like either of these?

• https://kstonedd14.files.wordpress.com/2015/02/circles-merge.jpg
• http://jwilson.coe.uga.edu/EMAT6680Su12/Carreras/EMAT6690/Essay2/circles[1].JPG

marco73it

Yes, circles that overlap like the ones in the pictures you shared. With Blobdetection they are detected as a single blob. OPENCV has the function Hough circle detect http://docs.opencv.org/2.4/doc/tutorials/imgproc/imgtrans/hough_circle/hough_circle.html However I have not understood how to implement it in processing.

jeremydouglass

@marco73it -- I'm not experienced in this specific type of problem, but one route might be to use the Processing OpenCV library --

https://github.com/atduskgreg/opencv-processing

-- then perhaps add hough circle detection -- I'm not sure if it is built in.