clear?all;
clc;
close?all;
I1?=?imread（‘12.bmp‘）;
I2?=?imread（‘18.bmp‘）;
[height1width1channel1]?=?size（I1）;
[height2width2channel2]?=?size（I2）;
I1?=?double（I1）;
I2?=?double（I2）;
average1?=?0;
average2?=?0;
k?=?0;
histogram1?=?zeros（1256）;
histogram2?=?zeros（1256）;
for?i?=?1:height1
????for?j?=?1:width1
????????k?=?I1（ij）;
????????m?=?I2（ij）;
????????average1?=?I1（ij）?+?average1;
????????average2?=?I2（ij）?+?average2;
????????histogram1（1k+1）?=?histogram1（1k+1）?+?1;
????????histogram2（1m+1）?=?histogram2（1m+1）?+?1;
????end
end

average1?=?average1/（height1*width1）???????????%圖1的平均灰度
average2?=?average2/（height1*width1）;