I calculated for a binary image the circularity using the regionprops function with this formula:
allCircularities1 = allPerimeters1.^2 ./ (4* pi*allAreas1);
I got the following circularity values : 2.933 ; 1.5260 ; 3.4890 ; 0.5380 ; 1.1568 0 ; 0 ; 0.5591.
I know that a circle has a circularity of nearly 1. As i understand the circularity is the roundness of an object / blob ? So my question is what the values greater 1 implicate? There isn't an object available that is 'rounder' than a circle.
My second question is the circularity value = 0. I checked the perimeter for that small blob. It also has the value 0. Why is that so ? Is the blob too small for the regionprops perimeter function ?