dct_matlab.rar_JPEG压缩 DCT_压缩编码_基于JPEG的DCT

function [a_tree code_huffman]=Huffman_encode(b) %clc;clear all;close all; container=[b(1)]; l_b=length(b); i_b=1; code_huffman=[]; count=zeros(1,l_b); count(1)=1; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%统计 for i_n=2:l_b i_m=1; while i_m<=i_b if b(i_n)==container(i_m) count(i_m)=count(i_m)+1; break; end i_m=i_m+1; end if i_m==i_b+1 container=[container b(i_n)]; i_b=i_b+1; count(i_b)=count(i_b)+1; end end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% value_min1=99999; value_min2=99999; l_container=length(container); tree=count(1:l_container); K=l_container; k=K; for i=1:K hf(i).weight=count(i); hf(i).parent=0; hf(i).cchild=0; hf(i).rchild=0; hf(i).flag=2; hf(i).value=container(i); end for i=K+1:2*K-1 hf(i).weight=0; hf(i).parent=0; hf(i).cchild=0; hf(i).rchild=0; hf(i).flag=2; end i_k=1; i=0; while(i_k<=k-1) m1=32767; m2=32766; x1=0; x2=0; for j=1:k+i if hf(j).weight<m1 &hf(j).flag==2 m2=m1; x2=x1; m1=hf(j).weight; x1=j; else if hf(i_k).weight<m2 & hf(j).flag==2 m2=hf(j).weight; x2=j; end end end hf(x1).flag=1; hf(x2).flag=0; i=i+1; hf(k+i_k).weight=hf(x1).weight+hf(x2).weight; hf(k+i_k).cchild=x1; hf(k+i_k).rchild=x2; hf(x1).parent=k+i_k; hf(x2).parent=k+i_k; i_k=i_k+1; end %%%%%*树的建立 for i_n=1:l_b for i_m=1:k if b(i_n)==hf(i_m).value c=i_m; top=0; p=hf(c).parent; hc=[]; while(p~=0) top=top+1; hc=[hc hf(c).flag]; c=p; p=hf(c).parent; end code_huffman=[code_huffman hc(length(hc):-1:1)]; end end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% end a_tree(1,:)=container; a_tree(2,:)=count(1:length(container));