which differences are between roundness and circularity?

hi

I want to do feature extraction from some objects in my binary image. I read some papers about roundness and circularity features. I can not understand the differences between these. can you help me to understand the differences? I am confused.

Answer 1

[Image Analyst]

People may use different definitions for example perimeter^2/(4*pi*area), or the inverse of that. You need to look at the actual formulas that they use. The formulas will tell you the differences. If you want to share the formulas, then I can tell you what the formulas do.

[jack nn]

thanks for your attention. in some papers I read different definition for example:

but in an other definition roundness and circularity are inverse of above definition

[Image Analyst]

Well I guess what I call circularity is what they call Compactness, and their Circularity is simply the inverse of that. The roundness looks similar to the ISO roundness definition https://en.wikipedia.org/wiki/Roundness_%28object%29