proj2_code.txt

matlab of analysis pictures

I = imread('coins','bmp'); 		
Ig = rgb2gray(I); 			
E = edge(Ig,'canny',0.7);
imshow(E);
title('Result of Edge Detection');
F = zeros(size(E));			% initialize all the entries in the accumulator cells	
for i=1:size(E,1),         % for every i and j do
    for j=1:size(E,2),
	
        if (E(i,j) == 1)		% check if it is an edge point
            for a=1:size(E,1),   
                side = (a-i) * (a-i); 		
                if (side <= 100) 				
                    s = 100 - side;  % obtain s by circle equation
                     s1=sqrt(s);	
				
                   % find the corresponding b and increment the cell value by 1 
   				    b = round(j - s1); 		
                    if (b > 0) 				
                        F(a,b) = F(a,b)+1; 			
                    end 	
					
                    b = round(j + s1); 			
                    if (b <= size(E,2)) 				
                        F(a,b) = F(a,b)+1; 			
                    end 				               
                end
            end
        end                   
    end
end
figure,imshow(uint8(F*20));
title('Accumulator cell');

value=max(max(F));    % find the maximum value in the accumulator cell
for a=1:4        
for i=1:size(E,1)         % check for every cells
    for j=1:size(E,2)
            if(F(i,j)==value)   % check if it is the maximum value 
               x= i;
               y= j;
                % mark centres with crosses
                    for c=i-5:i+5 
                      for d=j-1:j+1
                         F(c, d) = 0; 
                      end
                    end
                        for d=j-5:j+5 
                          for c=i-1:i+1
                            F(c, d) = 0;   
                          end
                        end
            Centre=[x;y]
			end	
    end
end
value=max(max(F));     % find the next maximum value in the accumulator cell    
end

figure,imshow(uint8(F*20))
title('Detection of centres(marked with cross)')