adaptivescript.m

Image segmentation script (code)

% ADAPTIVESCRIPT Script to open image file, set initial circle, and
% run narrow band algorithm on several different sizes of the
% image.

% constants
global ITERATIONS;
ITERATIONS = 25;
display_it = 100;
movie_it = inf;
scales = [ 0.1, 0.25, 0.375, 0.5, 0.75, 1.0 ];
iterations = [ 5000, 4000, 3000, 2000, 1000, 500 ];

% grab the image filename and path
[ filename, pathname ] = uigetfile( '*', 'Select an image to segment' );

% if user cancelled dialog box then exit
if( filename == 0 )
  return;
end;

% otherwise open the image and display it
im = readimage( strcat( pathname, filename ) );
im_resized = imresize( im, scales( 1 ) );
imshow( uint8( im_resized ) );

% and get the user to click on the circle center
disp( 'Click on circle center' );
center = ginput( 1 );

% display the center and get the user to click again to define the
% radius
disp( 'Click again to define radius' );
hold on;
plot( center(1), center(2), 'go-' );
hold off;
radius = round( sqrt( sum( ( center - ginput( 1 ) ).^2 ) ) )

% Get the user to pick whether the circle contains the object
disp( 'Choose whether or not entire object is inside circle' );
disp( '1. Completely Inside' );
disp( '2. Not Completely Inside' );

inside = 0;
while( inside ~= 1 & inside ~= 2 )
  inside = input( 'Please pick (1) or (2): ' );
end;

% determine movie name
moviename = filename( 1 : strfind( filename, '.' ) - 1 );

% initialize phi to signed distance function
phi = initphi( size( im_resized ), circshift( center, [ 0, 1 ] ), radius, inside );

% and run the level set segmentation
for i = 1 : size( iterations, 2 );
  % setup adaptive parameters
  ITERATIONS = iterations( i );
  im_resized = imresize( im, scales( i ) );
  phi = imresize( phi, size( im_resized ) );

  % perform segmentation at i'th level
  phi = levelsetbandadaptive( im_resized, display_it, movie_it, moviename, phi );
end;

im_segmented = createimage( im, phi );

% display the segmented image and save it to disk
clf; imshow( im_segmented ); drawnow;
imwrite( im_segmented, strcat( moviename, '_segmented.png' ) );