二值图像信息隐藏 二值图像信息隐藏算法与提取实验报告

clc;

clear all;

msgfid=fopen('hidden.txt','r'); %打开秘密文件

[msg,count]=fread(msgfid);

fclose(msgfid);

msg = str2bit(msg);

msg = msg';

count=count*8;

io=imread('erzhi.bmp'); %读入载体图像

watermarklen=count %嵌入水印信息长度，也就是载体图像分块的数量值

[row col]=size(io);

l1=floor(row/watermarklen); %载体图像分块后的长度

l2=floor(col/watermarklen); %载体图像分块后的宽度

pixelcount=l1*l2; %每个分块总像素的数量值

percent=ceil(pixelcount/2);

iw=io;

ioblack(1,watermarklen)=0; %某一个分块中黑色像素的个数

iowhite(1,watermarklen)=0; %某一个分块中白色像素的个数

n=1;

while n<=watermarklen

for i=l1*(n-1)+1:l1*n

for j=l2*(n-1)+1:l2*n

if io(i,j)==0

ioblack(1,n)=ioblack(1,n)+1; %计算每个分块中的黑色像素的个数

else

iowhite(1,n)=iowhite(1,n)+1; %计算每个分块中的白色像素的个数

end

end

end

n=n+1;

end

n=1;

while n<=watermarklen

if msg(n,1)==1 %需要嵌入1

if ioblack(1,n)>=percent; %嵌入1的时候，黑色像素比白色像素多，需要修改一些像素的颜色

modcount(1,n)=ioblack(1,n)-percent+1;

k=1;

for i=l1*(n-1)+1:l1*n

for j=l2*(n-1)+1:l2*n

if (iw(i,j)==0&&k<=modcount(1,n))

iw(i,j)=1;k=k+1;

end

end

end

end

else

if iowhite(1,n)>=percent; %嵌入0的时候，白色像素比黑色像素多，需要修改一些像素的颜色

modcount(1,n)=iowhite(1,n)-percent+1;

k=1;

for i=l1*(n-1)+1:l1*n

for j=l2*(n-1)+1:l2*n

if (iw(i,j)==1&&k<=modcount(1,n))

iw(i,j)=0;k=k+1;

end

end

end

end

end

n=n+1;

end

n=1;

iwblack(1,watermarklen)=0; %某一个分块中黑色像素的个数

iwwhite(1,watermarklen)=0; %某一个分块中白色像素的个数

while n<=watermarklen

for i=l1*(n-1)+1:l1*n

for j=l2*(n-1)+1:l2*n

if iw(i,j)==0

iwblack(1,n)=iwblack(1,n)+1; %计算每个分块中的黑色像素的个数

else

iwwhite(1,n)=iwwhite(1,n)+1; %计算每个分块中的白色像素的个数

end

end

end

n=n+1;

end

figure;

imshow('erzhi.bmp');

imwrite(iw,'erzhimarked.bmp');

figure;

imshow('erzhimarked.bmp');

clc;

clear all;

wi=imread('erzhimarked.bmp'); %读入载体图像

[row col]=size(wi);

watermarklen=48; %嵌入的水印信息的长度

l1=floor(row/watermarklen); %载体图像分块后的长度

l2=floor(col/watermarklen); %载体图像分块后的宽度

pixelblack(1,watermarklen)=0; %某一个分块中黑色像素的个数

pixelwhite(1,watermarklen)=0; %某一个分块中白色像素的个数

n=1;

while n<=watermarklen

for i=l1*(n-1)+1:l1*n

for j=l2*(n-1)+1:l2*n

if wi(i,j)==0

pixelblack(1,n)=pixelblack(1,n)+1; %计算每个分块中的黑色像素的个数

else

pixelwhite(1,n)=pixelwhite(1,n)+1; %计算每个分块中的白色像素的个数

end

end

end

n=n+1;

end

n=1;

while n<=watermarklen

if pixelwhite(1,n)>pixelblack(1,n) %如果白色像素块多于黑色像素块，秘密信息为1

message(n,1)=1;

else

message(n,1)=0; %如果黑色像素块多于白色像素块，秘密信息为0

end

n=n+1;

end

%将提取的秘密信息转换成字符串

out=bit2str(message);

fid=fopen('message.txt', 'wt');

fwrite(fid, out);

fclose(fid);

clc;

clear all;

oi=imread('erzhi.bmp'); %打开载体图像

[row col]=size(oi);

oi=oi(:);

len=size(oi);

i=1;

i=1;

j=1;

%统计游程长度

while i<len(1)

or=oi(i,1);

count=1;

while (i<len(1)&&oi(i+1,1)==or)

i=i+1;

count=count+1;

end

RLE(j)=count;

j=j+1;

i=i+1;

end

if i==len(1)

RLE(j)=1;

end

RLE=RLE';

msgfid=fopen('hidden.txt','r');%打开秘密文件

[msg,msgcount]=fread(msgfid);

fclose(msgfid);

msg = str2bit(msg);

msg = msg';

msgcount=msgcount*8;

for l=1:msgcount

modpoint=0;

for x=1:2*l

modpoint=modpoint+RLE(x,1);

end

if msg(l,1)==0

if ((mod(RLE(2*l,1),2)~=0)&&(RLE(2*1+1,1)~=1))

oi(modpoint+1,1)=mod((oi(modpoint+1,1)+1),2);

end

else

if ((mod(RLE(2*l,1),2)==0)&&(RLE(2*1+1,1)~=1))

oi(modpoint+1,1)=mod((oi(modpoint+1,1)+1),2);

end

end

end

%统计修改后的游程长度

len=size(oi);

i=1;

j=1;

while i<len(1)

or=oi(i,1);

count=1;

while (i<len(1)&&oi(i+1,1)==or)

i=i+1;

count=count+1;

end

RLE1(j)=count;

j=j+1;

i=i+1;

end

if i==len(1)

RLE1(j)=1;

end

RLE1=RLE1';

m1=Vector2Matrix(oi,row);%将数组转换成为二位矩阵

imwrite(m1,'watermarked.bmp');

figure;

imshow('erzhi.bmp');

figure;

imshow('watermarked.bmp');

clc;

clear all;

oi=imread('watermarked.bmp'); %打开携密图像

[row col]=size(oi);

oi=oi(:);

len=size(oi);

i=1;

i=1;

j=1;

while i<len(1)

or=oi(i,1);

count=1;

while (i<len(1)&&oi(i+1,1)==or)

i=i+1;

count=count+1;

end

RLE(j)=count;

j=j+1;

i=i+1;

end

if i==len(1)

RLE(j)=1;

end

RLE=RLE';

msgcount=80;

for i=1:msgcount

msg(i,1)=0;

end

for l=1:msgcount

if mod(RLE((2*l),1),2)==0

msg(l,1)=0; %如果游程的值为偶数，表示隐藏的信息为0

else

msg(l,1)=1; %如果游程的值为奇数，表示隐藏的信息为1

end

end

out=bit2str(msg);

fid=fopen('message1.txt', 'wt');

fwrite(fid, out);

fclose(fid);