function [pop]=initialise(popsize,stringlength,a,b)
% popsize=20;stringlength=8;
pop=zeros(popsize,stringlength+2);
  i=1; 
% for i=1:popsize
while i<=popsize
    pop1=round(rand(1,stringlength));
    sum=0;
    for k=1:stringlength
        sum=sum+pop1(k)*2^(k-1);
    end
     x=sum;%解碼
%      A=imread('pout.tif');
%      load woman;
%      A=imread('blood1.tif');
%  my=imread('mysaturn.tif');
% A=wiener2(my,[5 5]);
%  A=imnoise(a,'gaussian',0,0.05);
%     A=imread('kids.tif');
     a=imread('mytu.tif');
     
     count=imhist(A);
     [m,n]=size(A);
     N=m*n;
     L=256;
     count=count/N;
     u=0;
     for j=1:L
         u=u+count(j)*j;
     end
     
     w=0;ua=0;	
     for j=1:x
         w=w+count(j);
         ua=ua+count(j)*j;
     end
     if (w~=0)&(w~=1)
          eval1=(u*w-ua)^2/(w*(1-w));
          pop(i,1:stringlength)=pop1;
          pop(i,stringlength+1)=x;
          pop(i,stringlength+2)=eval1;
          i=i+1; 
      else
          i=i;
      end
      
 end