diameter of image (1024x1024 logical value)

Hello I have a 104x1024 logical.

when i use imshow(figure) to display it, it looks something like this

how do i get the diameter calculated?

i had already thought about the area but i don't know how.

this is an edited polar plot image

Thanks a lot

[Rik]

This is not a perfect circle, so which diameter do you want? Width, height, maximal, minimal, other?

Answer 1

[Image Analyst]

You can get the Equivalent Circular Diameter from regionprops(). This is the diameter of the blob if you were to smoosh and mold that same shape into a perfectly circular shape. In other words, the diameter of a perfect circle with the same number of pixels as your irregularly shaped blob.

props = regionprops(mask, 'EquivDiameter');
% Extract it from the structure into a simple variable.
ecd = props.EquivDiameter % This is the "Equivalent Circular Diameter".

Answer 2

[KSSV]

Let A be your logical of 1024*1024

[y,x] = find(A) ;       % get all th points with 1 
C = [mean(x) mean(y)] ;  % this gives the center of the region 
% Get the boundary 
idx = boundary(x,y) ; 
bx = x(idx) ; by = y(idx) ; 
% Get ditance 
d = sqrt((C(1)-bx).^2+(C(2)-by).^2) ; 
mind = min(d) ; 
maxd = max(d) ;