If I am given a image of black circle with white background, how can I find the exact center of that circle?

If I am given a image of black circle with white background, how can I find the exact center of that circle?

Answer 1

[Image Analyst]

You use regionprops and ask for the centroid. That's pretty much what I do in my Image Segmentation Tutorial http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862 except that I do it on the coins (standard demo image that ships with the Image Processing Toolbox) so it has several circles (coins), not just one.

[abhinav]

Thanks alot. your BlobsDemo program is nice.

Answer 2

[Evan]

Is this a binary image? If not, you'll need to do some thresholding. Once you do that, you can use regionprops (if you have the image processing toolbox installed).

spotC = regionprops(image_mask,'Centroid');

For more:

help regionprops

[abhinav]

thank you