algorithm for detecting a circle in an image

Question

I'm looking for an algorithm to detect circles in an image. The image is black and white. The background is white, and the circles don't overlap each other, or any other element in the image. The image includes some other shapes and some text.

If there is some open source .NET library to do this, I would also like to know about it.

Answer 1

Maybe the "Hough Transform" is useful for you. You have to know the circle's size in advance to make it efficient though.

• http://www.cis.rit.edu/class/simg782/lectures/lecture_10/lec782_05_10.pdf
• http://en.wikipedia.org/wiki/Hough_Transform

There was a similar question yesterday, where the "Hough Transform", and some image processing libraries (though not for .NET) were proposed:

http://stackoverflow.com/questions/3486789/image-processing-programming/3487137