Boundary of an image

Hi, How to mark boundary of an image. My given input image is collection of trees and my work is to count the no. of trees. I found the boundary line for each and every tree.. Boundary drawn looks like star shaped.. But i need it in the form of circle..

one circle per tree.

how to do this.

Regards, Siva

[Yash]

regionprops will work

Answer 1

[Ryan]

Utilize the matlab function regionprops(...,'MajorAxisLength'). This will return the diameter of a circle needed to enclose a region. You could also utilize regionprops(...,'BoundingBox') and use the maximum of the height/width as the diameter of the circle. You could then use the center of the 'BoundingBox' or 'centroid' to place the circles accurately for visualization puproses.