基于dct变换的图像编解码（包含Z扫描与反Z扫描）的matlab程序

function dct_code
orgbgr = imread('lena.jpg');
orggray = rgb2gray(orgbgr);
figure('color','white'),imshow(orggray),title('原始图像');
org = im2double(orggray);
D   = dctmtx(8);               //DCT变换矩阵
[m n] = size(orggray);
%使用的量化表
standard = [
1 1 1 1 0 0 0 0;
1 1 1 0 0 0 0 0;
1 1 0 0 0 0 0 0;
1 0 0 0 0 0 0 0;
0 0 0 0 0 0 0 0;
0 0 0 0 0 0 0 0;
0 0 0 0 0 0 0 0;
0 0 0 0 0 0 0 0;
];
%z 编排所用数组
z = [0  1  8 16  9  2  3 10
17 24 32 25 18 11  4  5
12 19 26 33 40 48 41 34
27 20 13  6  7 14 21 28
35 42 49 56 57 50 43 36
29 22 15 23 30 37 44 51
58 59 52 45 38 31 39 46
53 60 61 54 47 55 62 63];
z=z';z=z(:);
%% 编码程序
fdctdata = zeros(m,n);
for row = 1 : m/8
for col = 1 : n/8
src_tem = org((row-1)*8+1:(row-1)*8+8,(col-1)*8+1:(col-1)*8+8);
fdctdata((row-1)*8+1:(row-1)*8+8,(col-1)*8+1:(col-1)*8+8) = D * src_tem * D';
end
end
%量化DCT系数
for row = 1 : m/8
for col = 1 : n/8
for i=1:8
for j=1:8
fdctdata((row-1)*8+i,(col-1)*8+j) = fdctdata((row-1)*8+i,(col-1)*8+j)*standard(i,j);
end
end
end
end
%Z型扫描
zdata = zeros(512*512,1);
ind = 1;
cout = 1;
for i = 1 : 8
for j = 1 : 8
for row = 1 : m/8
for col = 1 : n/8
zdata(ind) = fdctdata((row-1)*8+floor(z(cout)/8)+1,(col-1)*8+mod(z(cout),8)+1);
ind = ind + 1;
end
end
cout = cout+1;
end
end

%% 解码程序
%反Z型扫描
ifdctdata = zeros(m,n);
ind = 1;
cout = 1;
for i = 1 : 8
for j = 1 : 8
for row = 1 : m/8
for col = 1 : n/8
ifdctdata((row-1)*8+floor(z(cout)/8)+1,(col-1)*8+mod(z(cout),8)+1) = zdata(ind);
ind = ind + 1;
end
end
cout = cout+1;
end
end
%反DCT变换
for row = 1 : m/8
for col = 1 : n/8
dct_tem = ifdctdata((row-1)*8+1:(row-1)*8+8,(col-1)*8+1:(col-1)*8+8);
ifdctdata((row-1)*8+1:(row-1)*8+8,(col-1)*8+1:(col-1)*8+8) = D' * dct_tem * D;
end
end
figure('color','white'),imshow(ifdctdata,[]),title('反变换恢复图像');