How i can find and calculate the diameter?

Halo, I have a region of interest detected by a segmentation method and canny edge detection. I want to find and calculate the diameter of this region. How can i do this with matlab? This is the mask of the region.

thanks

Answer 1

[Image Analyst]

Is the perimeter solid, or does it have gaps in it? First of all, crop away that gray border. Then call imfill(binaryImage, 'holes') to make it solid. Then call regionprops() and ask for EquivDiameter. See my Image Segmentation Tutorial for a full demo. http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862

croppedImage = grayImage(row1:row2, col1:col2);
binaryImage = croppedImage > 128; % Only if it's not already binary.
binaryImage = imfill(binaryImage, 'holels');
labeledImage = bwlabel(binaryImage);
measurements = regionprops(labeledImage, 'EquivDiameter');
EquivalentCircularDiameter = measurements.EquivDiameter

[Indra Ginanjar A.T]

thankyou sir, how about using fit ellipse algorithm? it can?

[Walter Roberson]

regionprops() 'MajorAxisLength' and 'MinorAxisLength' more or less fits an ellipse.