clear;
clc;

org_img?=?imread（‘a(chǎn).jpg‘）;
org_img?=?double（rgb2gray（org_img））;
[xy]?=?size（org_img）;
%補全矩陣獲得子圖像
if?x?>?y
????sub_img?=?zeros（x）;
????N?=?x;
????for?i?=?1?:?x
????????for?j?=?1?:?y
????????????sub_img（ij）?=?org_img（ij）;
????????end
????end
else
????sub_img?=?zeros（y）;
????N?=?y;
????for?i?=?1?:?x
????????for?j?=?1?:?y
????????????sub_img（ij）?=?org_img（ij）;
????????end
????end
end
%根據(jù)公式計算DCT結(jié)果
c?=?zeros（N）;
for?i?=?1?:?N
????for?j?=?1?:?N
????????if?i?==?1
????????????a?=?sqrt（1/N）;
????????else
????????????a?=?sqrt（2/N）;
????????end
????????c（ij）?=?a?*?cos（pi*（j-1+0.5）*（i-1）/N）;