BMP图像信息隐藏

在BMP图像中隐藏信息

 1 clc;
 2 clear;
 3 fid = fopen('baboon.bmp', 'r');
 4 [a,length] = fread(fid,inf,'uint8');
 5 fclose(fid);
 6 msgfid = fopen('hidden.txt','r');
 7 [msg,count] = fread(msgfid);
 8 fclose(msgfid);
 9 new_picture_array = a(1:54);  %把文件头复制给新数组
10 new_picture_array(11) = 54 + count; %修改文件偏移
11 new_picture_array(3) = new_picture_array(3) + count;% 修改文件大小
12 j = 1;
13 for i = 55:54+count
14     new_picture_array(i) = uint8(msg(j)); %把信息隐藏在新的图像数组中
15     j = j + 1;
16 end
17 for i=55+count:length+count
18     new_picture_array(i) = a( i - count); % 把隐藏前文件的数据部分复制到新数组中
19 end
20 new_picture_array = uint8(new_picture_array);
21 fid = fopen('bmpheadhiding.bmp','wb'); %新建一个bmp图像
22 fwrite(fid, new_picture_array);%把带有隐藏信息的数组写入bmp图像
23 fclose(fid);

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