Circularity = -1 ??

[Richard Han-2]

Dear ImageJ users

I am measuring the circularity of cells. I noticed there are  
circularity values equal to -1. What does -1 in circularity mean?

Thanking you

Richard Han
Hospital for Small Animals
Easter Bush Veterinary Centre
University of Edinburgh
Roslin
Midlothian
EH25 9RG
UK

Tel: [phone]
E-mail: [hidden email]

[Wayne Rasband]

> I am measuring the circularity of cells. I noticed there are
> circularity values equal to -1. What does -1 in circularity mean?

It means that the calculated circularity value was greater than 1.0,
which can happen with very small particles. In ImageJ 1.37, circularity
values greater than 1.0 are set to 1.

-wayne