I want to find out the x,y co-ordinates of the minor and major axis of an elliptical shaped portion in my Image.

I have a binary image, in that I have a shape similar to an ellipse(this ellipse is distorted a bit). I want to find out the major and minor axes of that ellipse. I have tried using regionprops. C=regionprops(H,'ConvexHull','MinorAxisLength','MajorAxisLength'); It is of no help as it gives me only the length of it and not the co-ordinates of those points that after being joined gives us the minor and major axes respectively. It would be really nice if you could help me find the endpoints of those axes.

Answer 1

[Image Analyst]

Use bwboundaries() to get the perimeter (x,y) coordinates, then use the FAQ: http://matlab.wikia.com/wiki/FAQ#How_can_I_fit_an_ellipse_or_other_shape_to_a_set_of_XY_data.3F

[Amit Nambiar]

Thanks a lot Sir, I will try doing this and let you know if this method worked. I had read your tutorial on Image thresholding and found it to be very helpful.