BBHE Code not working on Color Images

a=imread('C:\Users\Ritu\Documents\dez\bot.png');

b = a(:,:,1);

imshow(b); figure, imhist(b); sz=size(b); o_mean = round(mean(b(:)));

 h_l = zeros(256,1);
   h_u = zeros(256,1);

   for i = 1:sz(1)
       for j = 1:sz(2)
           g_val = b(i,j);
            if(g_val<=o_mean)
             h_l(g_val+1) = h_l(g_val+1) + 1;
           else
              h_u(g_val+1) = h_u(g_val+1) + 1;
           end
       end
  end
  disp(h_l)
  disp(h_u)

    %pdf
   nh_l = h_l/sum(h_l);
   nh_u = h_u/sum(h_u);

   %cdf
   hist_l_cdf = double(zeros(256,1));
   hist_u_cdf = double(zeros(256,1));
   hist_l_cdf(1) = nh_l(1);
   hist_u_cdf(1) = nh_u(1);

   for k = 2:o_mean
       hist_l_cdf(k) =  hist_l_cdf(k-1) + nh_l(k);
   end
   for k=2:256
       hist_u_cdf(k) =  hist_u_cdf(k-1) + nh_u(k);
   end

   equalized_img = zeros(sz);
   range_l = [0 o_mean];
   range_u = [(o_mean+1) 255];
   for i =1:sz(1)
       for j =1:sz(2)
           g_val = b(i,j);
           if(g_val<=o_mean)
              equalized_img(i,j) = range_l(1) + round(((range_l(2)-range_l(1))*hist_l_cdf(g_val+1))); 
           else
              equalized_img(i,j) = range_u(1) + round(((range_u(2)-range_u(1))*hist_u_cdf(g_val+1))); 
           end
      end
   end
   o=mat2gray(equalized_img);
figure, imshow(o);
figure, imhist(o);

[CSE]

please give me answer as soon as possible so that i can process my coding further.

[CSE]

please anyone give me any solution.

[pankaj swaroop]

To run it on rgb. Follow this

1. Save the above code with name BBHE and first line:

function BBHE(a)

2. Then run these line to get output image which would improve the contrast of rgb image

out1=BBHE(a(:,:,1));
out2=BBHE(a(:,:,2));
out3=BBHE(a(:,:,3));
figure
imshow(cat(3,out1,out2,out3));