MATLAB图像数字水印方案毕业论文论文+源码

%Name:		Chris Shoemaker
%Course:	EER-280 - Digital Watermarking
%Project: 	CDMA based using multiple PN sequences embeded into whole object
%           Watermark embeding

clear all;

% save start time
start_time=cputime;

k=2;                % set the gain factor for embeding

% read in the cover object
file_name=‘_lena_std_bw.bmp‘;
cover_object=double（imread（file_name））;

% determine size of watermarked image
Mc=size（cover_object1）;	%Height
Nc=size（cover_object2）;	%Width

% read in the message image and reshape it into a vector
file_name=‘_copyright_small.bmp‘;
message=double（imread（file_name））;
Mm=size（message1）;	                        %Height
Nm=size（message2）;	                        %Width
message_vector=round（reshape（messageMm*Nm1）./256）;

% read in key for PN generator
file_name=‘_key.bmp‘;
key=double（imread（file_name））./256;

% reset MATLAB‘s PN generator to state “key“
rand（‘state‘key）;

watermarked_image=cover_object;

% when message contains a ‘0‘ add pn sequence with gain k to cover image
for kk=1:length（message_vector）
    pn_sequence=round（2*（rand（McNc）-0.5））;
    
    if message（kk） == 0
        watermarked_image=watermarked_image+k*pn_sequence;
    end
end

% convert back to uint8
watermarked_image_uint8=uint8（watermarked_image）;

% write watermarked Image to file
imwrite（watermarked_image_uint8‘cdma_watermarked.bmp‘‘bmp‘）;

% display processing time
elapsed_time=cputime-start_time

% calculate the PSNR
psnr=psnr（cover_objectwatermarked_image_uint8McNc）

% display watermarked Image
figure（1）
imshow（watermarked_image_uint8[]）
title（‘Watermarked Image‘）