www.pudn.com > ms_segmenter.rar > M_shift3.m

function [Mode, Number_values] = M_shift3 (Values, Window_radius, Initial) 
% 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 = size(Values, 1);L2 = size(Values, 2);L3 = size(Values, 3); 
Min_number_values = 1; % Window_radius^4 
 
while norm(Next_val-Current_val) > 1 
   Current_val = Next_val; 
   clear x; 
   [x(1, :, :, :), x(2, :, :, :), x(3, :, :, :)] = ... 
      ndgrid(... 
      [max(1, Current_val(1)-Window_radius): ... 
      min(L1, Current_val(1)+Window_radius)], ... 
      [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(... 
      max(1, Current_val(1)-Window_radius): ... 
      min(L1, Current_val(1)+Window_radius), ... 
      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)); 
    
   for i=1:3 
      Sum_values(1, i) = sum(sum(sum(squeeze(x(i, :, :, :)) .* Window))); 
   end 
    
   Number_values = sum(sum(sum(Window))); 
    
   if Number_values < Min_number_values 
      Mode = Initial; 
      Number_values = 0; 
      return; 
   end 
    
   Next_val = round(Sum_values/Number_values); 
end 
Mode = Next_val;