Obtaining the best ellipse fit of an irregular shape

Say that we have an irregular shape. How can we obtain the best `ellipse` fit of such shape? Does `regionprops` work for that? If so, can you kindly guide me on that?

Thanks.

Answer 1

[Sean de Wolski]

http://www.mathworks.com/matlabcentral/fileexchange/index?utf8=%E2%9C%93&term=fit+ellipse

Use one of those functions on the row/col coordinates of the pixels in the object

Answer 2

[Image Analyst]

Yes, regionprops can probably do what you want. Check out Steve's blog for a demo. http://blogs.mathworks.com/steve/2010/07/30/visualizing-regionprops-ellipse-measurements/

To find ellipses in a gray scale image you might check out http://www.ecse.rpi.edu/homepages/qji/Papers/ellipse_det_icpr02.pdf

You might also check out this paper:

Pattern Recognition 34 (2001) 2283}2303
Least-squares orthogonal distances Fitting of circle, sphere, ellipse, hyperbola, and parabola
Sung Joon Ahn, Wolfgang Rauh, Hans-Jurgen Warnecke