www.pudn.com > Ms_segmenter.rar > M_shift3_sps.m

function [Mode, Number_values, Flag] = M_shift3 (Values, Window_radius, Initial, Min_number) 
% assumes that Values contains cumulative information, i.e. 
% the number of elements of the particular value in each Values cell 
 
Current_val = round(Initial+2);Next_val = round(Initial); 
L1 = length(Values); 
L2 = size(Values{1}, 1); 
L3 = size(Values{1}, 2); 
 
while norm(Next_val-Current_val) > 1 
   Current_val = Next_val; 
   clear x; Sum_values(1, 1:3) = zeros(1, 3);Number_values = sparse(1, L1); 
   for i=max(1, Current_val(1)-Window_radius):min(L1, Current_val(1)+Window_radius) 
      [x(1, :, :), x(2, :, :)] = ... 
         ndgrid(... 
         [max(1, Current_val(2)-Window_radius): ... 
            min(L2, Current_val(2)+Window_radius)], ... 
         [max(1, Current_val(3)-Window_radius): ... 
            min(L3, Current_val(3)+Window_radius)]); 
       
      Window = Values{i}(... 
         max(1, Current_val(2)-Window_radius): ... 
         min(L2, Current_val(2)+Window_radius), ... 
         max(1, Current_val(3)-Window_radius): ... 
         min(L3, Current_val(3)+Window_radius)); 
       
      Number_values(i) = sum(sum(Window)); 
      Sum_values(1, 1) = Sum_values(1, 1) + Number_values(i)*i; 
       
      for j=1:2 
         Sum_values(1, j+1) = Sum_values(1, j+1)+sum(sum(squeeze(x(j, :, :)) .* Window)); 
      end 
   end 
    
   Number_values_sum = sum(Number_values); 
    
   if Number_values_sum < Min_number 
      Mode = Initial; 
      Flag = 1; 
return; 
   end 
    
   Next_val = round(Sum_values/Number_values_sum); 
end 
% Mode = Next_val; 
Mode = Current_val; 
Flag = 0;