Finding only circular objects?

I have a binary image with different shapes of objects. I want to calculate the number of only circular objects in the image. How can I do that by using regionprops function?

Thanks

Answer 1

[Image Analyst]

You can compute the circularity. See my attached shape recognition demo.

[rupam baruah]

Thnks. How can I calculate total number of circles (suppose circulartity threshold is .85) in the image. Is there any particular function to find that thing? Thnks

[Image Analyst]

use ismember and bwlabel

labeledImage = bwlabel(binaryImage);
measurements = regionprops(labeledImage, 'Area', 'Perimeter');
allAreas = [measurements.Area];
allPerimeters = [measurements.Perimeter];
circularities = 4*pi*allAreas ./ allPerimeters.^2;
circleIndexes = find(circularities > 0.85);
circlesOnlyImage = ismember(labeledImage, circleIndexes) > 0;
[labeledImage, numCircles] = bwlabel(circlesOnlyImage);