www.pudn.com > balloonSnake(matlab).rar > balloon_ex.m

% EXAMPLE     an example of balloon model on the room object 
% 
 
%   Chenyang Xu and Jerry Prince 6/17/97 
%   Copyright (c) 1996-97 by Chenyang Xu and Jerry Prince 
 
   cd ..;   s = cd;   s = [s, '/snake']; path(s, path); cd examples; 
    
   help balloon_ex; 
 
   % Read in the 64x64 room image 
     [I,map] = rawread('../images/room.pgm');   
      
   % Compute its edge map 
     disp(' Compute edge map ...'); 
     f = 1 - I/255;  
     f0 = gaussianBlur(f,1); 
     % note: snake potential is the negative of edge map 
     disp(' Comute the traditional external force ...'); 
     [px,py] = gradient(f0); 
 
   % display the results 
     figure(1);  
     subplot(121); imdisp(-f); title('snake potential'); 
     subplot(122); quiver(px,py);  
     axis('image', 'ij', 'off');   % fix the axis  
     title('traditional force'); 
                
   % balloon deformation 
     disp(' '); 
     disp(' Press any key to start the deformation'); 
     pause; 
     figure(1); subplot(121);   
     colormap(gray(64));  
     image(((1-f)+1)*40); axis('square', 'off'); 
     t = 0:0.5:6.28; 
     x = 32 + 3*cos(t); 
     y = 32 + 3*sin(t); 
     [x,y] = snakeinterp(x,y,2,0.5); 
     snakedisp(x,y,'r')  
     pause(1); 
 
     for i=1:15, 
       [x,y] = snakedeform2(x,y,0.05,0,1, 2, 0.15,px,py,5); 
       [x,y] = snakeinterp(x,y,2,0.5); 
       snakedisp(x,y,'r')  
       title(['Deformation in progress,  iter = ' num2str(i*5)]) 
       pause(0.5); 
     end 
 
     disp(' '); 
     disp(' Press any key to display the final result'); 
     pause; 
     figure(1); subplot(121);   
     colormap(gray(64));  
     image(((1-f)+1)*40); axis('square', 'off'); 
     snakedisp(x,y,'r');  
     title(['Final result,  iter = ' num2str(i*5)]);