btc1.m

将一幅多媒体图像根据各个块的不同特性蔡用不同的编码方式

function btc1(a2)
global point cell_count total_cell

weishu=size(a2);
changdu=weishu(1)*weishu(2);
a=double(reshape(a2,1,changdu));
meanvl=mean(a');% btc编码

 m=0;
 for i=1:changdu
     m=m+a(i)^2;
 end
 coval=m/changdu-meanvl^2;
     
                                  q=0;
                                  for ii=1:changdu
                                      if a(ii) >= meanvl;
                                          g(ii)=(1);
                                          g1(ii)=(g(ii)-1);
                                          q=q+1;
                                      else
                                          g(ii)=(0);
                                          g1(ii)=(g(ii)+1);
                                      end
                                  end
                                  if coval==0
                                      a0=meanvl;a1=meanvl;
                                  else
                                      a0=meanvl-(coval*q/((16-q)+eps))^(1/2) ;     
                                      a1=meanvl+(coval*(16-q)/(q+eps))^(1/2) ;     
                                  end
                                  
                                  
                                  
                                  %return;

                                total_cell(point+1)=(a0); total_cell(point+2)=(a1);
                                %point=point+1;
                                for i=1:8
                                     bma1(i)=int2str(g(i));
                                end 
                                total_cell(point+3)=(bin2dec(bma1));%uint8 delete
                               
                                for j=1:8
                                    bma2(j)=int2str(g(j+8));
                                end
                                total_cell(point+4)=(bin2dec(bma2));%uint8 delete
                                point=point+4;
                                cell_count=cell_count+4;