emag = imread('edge3.tif');

Thigh = 160
Tlow  = 20

Ehigh = emag>Thigh;
Elow  = (Tlow<=emag) & (emag<=Thigh);

figure(1)
subplot(2,2,1); imshow(emag, [])
subplot(2,2,2); imshow(Ehigh, [])

s=1;
while s>0
    d = bwdist(Ehigh, 'chessboard');
    %d = bwdist(Ehigh, 'cityblock');
    d(Elow==0)=0;
    X = (d==1);
  
    Ehigh = Ehigh | X;

    subplot(2,2,3); imshow(X, [])
    subplot(2,2,4); imshow(Ehigh, [])
    s=sum(X(:))
    pause(0.1)
end

pause(5)
subplot(2,2,3);imshow(Tlow<=emag, [])


if 0
  L = bwlabel(Ehigh,8);
  stats = regionprops(L, 'Area');

  idx = find([stats.Area] >= 30);
  E = ismember(L,idx);
  figure(2); imshow(E, [])
  figure(3); imshow(L, [])
end