color video error

I try to extract the keyframe usin entropy way,current,I test video that is gray and size is [288 252 300]. But now,I must to use color video that size is [480 640 3 207] row and colum is 480 640 and 3 is color(RGB)and 207 is frames.

this is my code,current

clear all;
load xz

[m,n,c,f]=size(xz);

h=zeros(1,256);
e=zeros(1,207);
a=zeros(1,207);
dif=zeros(1,207);
se=zeros(1,207);
b=zeros(1,207);

for ix=1:207;    

          h=zeros(1,256);    
              for ii=1:m

                  for jj=1:n

                    c=1;

                          h(xz(ii,jj,c,ix)+1)= h(xz(ii,jj,c,ix)+1)+1;   
                  end
              end

              figure(1)
              plot(h)

              pf=h/(m*n);
              figure(2)
              plot(pf)

              for ii=1:256
                  if(pf(ii)==0)   % pr為0，則q(消息量)為0
                      q(ii)=0;
                else
                      q(ii)=-1.*log2(pf(ii));    %pr不為0，則用log去計算出q(消息量)
                  end
              end

              ef=pf.*q;   

              e(ix)=sum(pf.*q);     

          em=sort(ef,2,'descend');

          s=0;
          for k=1:256
             s=s+em(k);

             if (s>=0.7*e(ix) )
                se(ix)=s; 
               break;   

              end
          end
       a(ix)=k;  

       s=0;
       for k=a(ix):256
             s=s+em(k);
       end
       b(ix)=s;  
   end

   for ix=1:207

       if(ix<207)
         dif(ix)=abs(b(ix)-b(ix+1));

         if(dif(ix)>0.1)
         ix
        end
       end

   end

I refer to the algorithm of this paper http://kawicho.com/iat333/IAT455%20_IGNOR/useful_.pdf

Please give me some advices. Thanks!

[Walter Roberson]

What error is encountered on which line? Or how does the output differ from what you expect?