how to find the dimension of the biggest component?

hi all,

I need to find the dimension of the biggest components.Then plotted against p=linspace(0,1,10).

N=10
for i=1:N
  for j=1:N
    if rand(1,1)<0.55
      A(i,j)=1;
    else
      A(i,j)=0;
    end
  end
end

CC = bwconncomp(A,4);

numPixels = cellfun(@numel,CC.PixelIdxList);

[biggest,idx] = max(numPixels);

A(CC.PixelIdxList{idx}) = 2

colours=[1 1 1;0 0 0;1 0 0]
colormap (colours)
imagesc(A)

[Jan]

Please explain uniquely what "the biggest components" are. What problems do you have with the posted code?

[Sultan]

biggest component is the component who has biggest number of pixels. The problem is that i want to find the dimension of it

Answer 1

[Image Analyst]

You can use regionprops() to find the axis of an ellipse fitted to the data. They don't give you the Feret (caliper) diameter, so you can adapt my attached code to give you that.

[Sultan]

can you provide more help, still not clear

[Image Analyst]

Sure. Attach your image and segmentation algoritm to produce your binary image. Then you can use my Image Segmentation Tutorial http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862&sort=downloads_desc to find out how to find all the areas of your blobs. Next, tell me which blob(s) you want the maximum extent (width) computed for. All of them? Just for the one with the greatest area?