function [m,ws] =  mmiwatershed( f, Bc )
%  MMIWATERSHED Interactive watershed from markers.
%
%  [M,WS] =  MMIWATERSHED( F, BC )
%
%  Input:
%    F - Gray-scale (uint8 or uint16) or binary image (logical uint8).
%    BC - Structuring element. Connectivity. DEFAULT: mmsecross.
%
%  Output:
%    [M,WS] - Gray-scale (uint8 or uint16) or binary image (logical
%        uint8).
%
%  The image is interactively segmented by placing markers with the
%    mouse. The markers are placed by pointing the mouse and press any
%    mouse button or key. Each key is associated to a different label,
%    so the user can choose different keys to segment different
%    regions.  As the markers are placed, the image is segmented and
%    the result presented immediately to the user. If DEL or BACK-
%    SPACE is pressed on a marker, it is deleted. The key ESC is used
%    to exit. Internally, the watershed is computed on the
%    morphological gradient of the input image.
%
%  See also MMCWATERSHED, MMFREEDOM, MMSEBOX, MMSECROSS.

% begin of the default argument automatic treatment

if ~exist('Bc','var') Bc = mmsecross; end
% end of the default argument automatic treatment 1

disp('Interactive watershed, press ESC to exit');
mmshow(f);
g=mmgradm(f,Bc,Bc);
m=mmintersec(f,uint8(0));
z=m;

button=1;
while 1
 [x, y, button]=ginput(1);
 if button==27; break; end;      % ESC: Exit
 if ((button==127) | (button==8))% DEL,BS: remove marker
   aux=z;
   z(y,x)=uint8(255);
   m=mmintersec(m,mmneg(mmdil(z,mmsedisk(3))));
   fprintf('Marker deleted\n');
 else                        % else place marker
   m(y,x)=button;
   fprintf('Region %2.0f\n',button);
 end
 ws=mmcwatershed(g,mmdil(m),Bc);
 mmshow(f,ws,mmbinary(mmdil(m)));
 drawnow;
end


%  Copyright (c) 1998-2001 by SDC Information Systems.