function?checksum_embed（）

clear?all;?

%?save?start?time?
start_time?=?cputime;?
?
%?read?the?original?image?
file_name?=?‘lena.bmp‘;?
ori_img?=?imread（file_name）;?
?
%?compute?size?of?the?original?image
H?=?size（ori_img?1）;	%?height?
W?=?size（ori_img?2）;	%?width
num?=?H?*?W;???%?the?number?of?pixels
?
%?get?2~8?bits?from?each?8?pixels
line?=?ceil（num/8）;
binarray?=?zeros（line?56）;
k?=?1;
m?=?0;
for?i?=?1?:?H?
????for?j?=?1?:?W
????????if?m?>?7
????????????m?=?0;
????????????k?=?k?+?1;?
????????end
????????binarray（k?7?*?m?+?1）?=?bitget（ori_img（i?j）?8）;
????????binarray（k?7?*?m?+?2）?=?bitget（ori_img（i?j）?7）;
????????binarray（k?7?*?m?+?3）?=?bitget（ori_img（i?j）?6）;
????????binarray（k?7?*?m?+?4）?=?bitget（ori_img（i?j）?5）;
????????binarray（k?7?*?m?+?5）?=?bitget（ori_img（i?j）?4）;
????????binarray（k?7?*?m?+?6）?=?bitget（ori_img（i?j）?3）;
????????binarray（k?7?*?m?+?7）?=?bitget（ori_img（i?j）?2）;
????????m?=?m?+?1;
????end
end

%?compute?watermark
binarray?=?uint8（binarray）;
watermark?=?zeros（1?56）;
watermark?=?uint8（watermark）;
for?k?=?1?:?line
????watermark（1?:）?=?bitxor（watermark（1?:）?binarray（k?:））;
end
?
%?set?the?lsb?of?56?pixels?of?the?original?images?to?the?value?of?watermark
k?=?1;
watermarked_img?=?ori_img;
for?i?=?1?:?H
????for?j?=?1?:?W
????????if?k?<=?56
????????????watermarked_img（i?j）?=?bitset（watermarked_img（i?j）?1?watermark（1?k））;
????????????k?=?k?+?1;
????????end
????end
end
?
%?write?the?watermarked?image?to?a?file?
imwrite（watermarked_img‘watermarked_lena.bmp‘‘bmp‘）;?
?
%?display?processing?time?
elapsed_time=cputime-start_time

%?calculate?the?PSNR?
psnr_value?=?psnr（ori_imgwatermarked_img）
?
%?display?watermarked?image?
figure（1）?
imshow（watermarked_img[]）?
title（‘Watermarked?Image‘）?
figure（2）?
imshow（ori_img[]）?
title（‘Original?Image‘）??

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件????5512725??2011-04-28?17:25??應(yīng)用Matlab實現(xiàn)數(shù)字水印.pptx

?????文件???????1893??2011-04-20?16:55??checksum實驗\checksum_embed.m

?????文件???????1698??2011-04-21?21:05??checksum實驗\checksum_recover.m

?????文件?????148536??2011-04-21?18:32??checksum實驗\distort_lena.bmp

?????文件?????148534??2011-04-20?10:37??checksum實驗\lena.bmp

?????文件????????618??2011-04-20?15:44??checksum實驗\psnr.m

?????文件?????148534??2011-04-20?15:45??checksum實驗\watermarked_lena.bmp

?????文件??????14622??2010-04-20?10:21??lsb實驗\key.bmp

?????文件?????148534??2010-04-20?10:21??lsb實驗\lena.bmp

?????文件???????1732??2011-04-07?14:32??lsb實驗\lsb_embed.m

?????文件???????1801??2011-04-21?18:16??lsb實驗\lsb_recover.m

?????文件????????893??2011-04-07?09:39??lsb實驗\psnr.m

????..A.SH.?????19968??2010-12-14?21:18??lsb實驗\Thumbs.db

?????文件?????148534??2010-04-20?10:21??nec實驗\lena.bmp

?????文件???????4629??2011-04-07?09:39??nec實驗\nec.m

?????文件????????893??2011-04-07?09:39??nec實驗\psnr.m

????..A.SH.?????30720??2010-12-14?21:19??nec實驗\Thumbs.db

?????文件?????148534??2010-04-20?10:21??patchwork實驗\lena.bmp

?????文件???????1263??2011-04-07?15:44??patchwork實驗\patchwork_embed.m

?????文件???????3770??2011-04-21?18:22??patchwork實驗\patchwork_recover.m

?????文件????????893??2011-04-07?09:39??patchwork實驗\psnr.m

????..A.SH.?????30720??2010-12-14?21:19??patchwork實驗\Thumbs.db

?????文件????????510??2011-04-21?15:52??基本圖像處理實驗\blkproc1.m

?????文件????????120??2011-04-21?17:42??基本圖像處理實驗\brighten1.m

?????文件?????????84??2011-04-21?15:28??基本圖像處理實驗\dct1.m

?????文件??????66988??2011-04-19?14:24??基本圖像處理實驗\df.jpg

?????文件????????249??2011-04-21?18:14??基本圖像處理實驗\filter21.m

?????文件?????????68??2011-04-21?16:24??基本圖像處理實驗\histeq1.m

?????文件?????????82??2011-04-19?15:29??基本圖像處理實驗\imadjust1.m

?????文件????????121??2011-04-21?12:29??基本圖像處理實驗\image1.m

............此處省略22個文件信息