MATLAB 水印嵌入函数 - wm(I,w,g)

MATLAB 水印嵌入函数 - wm(I,w,g)

此函数为嵌入过程，使用小波变换将水印信息嵌入图像。

输入：

• I：原始图像
• w：水印信息（二进制矩阵）
• g：水印嵌入的阈值

输出：

• J：嵌入水印的图像

代码:

function J = wm(I,w,g)
% 此函数为嵌入过程
% 输入：I为原始图像；w为水印信息；g为水印嵌入的阈值
% 输出：J为嵌入水印的图像
%%
% 参数设置
step = 0.5; % 小波系数增长步长
%%
[mm,nn] = size(I);
% 一层小波分解
[LL,LH,HL,HH] = dwt2(I,'haar');
%=======计算avr_LH======
[m0,n0] = size(LH); avr_LH = 0;



%=======计算avr_HL======
[m1,n1] = size(HL); avr_HL = 0;


% 判断嵌入的子带
if avr_LH <= avr_HL
    num = 0; loca = LH;
else
    num = 1; loca = HL;
end

%%
% 嵌入水印
if num == 0
    loca = wm_type_0(loca,w,step,g);  % LH是横向，写出嵌入子函数
else
    loca = wm_type_1(loca,w,step,g);  % HL是纵向，写出嵌入子函数
end
%%
if num == 0
    LH = loca; 
else
    HL = loca; 
end
J = idwt2(LL,LH,HL,HH,'haar',[mm,nn]);   % 小波逆变换，还回原始图像
                

已知代码wm_type_0:

function loca = wm_type_0(loca,w,step,g)
% 此函数用于在HL子带嵌入水印
% 输入：loca为要嵌入水印的子带
% 输出：loca为嵌入水印后的子带

[m2,n2] = size(loca);
index = 1;
% 取出2*2的块
for k = 1:2:m2-1
    for kk = 1:2:n2-1
        tem = loca(k:k+1,kk:kk+1);
        a11 = tem(1,1);
        a12 = tem(1,2);
        a21 = tem(2,1);
        a22 = tem(2,2);
        if 0 == w(index)
            for s = step:step:100*step
                if a11-a12<=g   % 如果满足条件，a11增，a21减
                    a11 = a11 + s;
                    a12 = a12 - s;
                else
                    break;     % 不满足条件，跳出此循环
                end
            end
            %-----如果a21和a22不满足条件，则也要调整------------
            if a21-a22<=g
                a21 = a21 + s;
                a22 = a22 - s;
            end
            tem(1,1) = a11;
            tem(1,2) = a12;
            tem(2,1) = a21;
            tem(2,2) = a22;
            loca(k:k+1,kk:kk+1) = tem;
            
        end
        if 1 == w(index)
            for s = step:step:100*step
                if a11-a12>=-g   % 如果满足条件，a11增，a21减
                    a11 = a11 - s;
                    a12 = a12 + s;
                else
                    break;     % 不满足条件，跳出此循环
                end
            end
            %-----如果a21和a22不满足条件，则也要调整------------
            if a21-a22<=g
                a21 = a21 + s;
                a22 = a22 - s;
            end
            tem(1,1) = a11;
            tem(1,2) = a12;
            tem(2,1) = a21;
            tem(2,2) = a22;
            loca(k:k+1,kk:kk+1) = tem;
            
            
            
        end
        index = index + 1;
        tem(1,1) = a11;
        tem(1,2) = a12;
        tem(2,1) = a21;
        tem(2,2) = a22;
        loca(k:k+1,kk:kk+1) = tem;
    end
end

给出wm_type_1代码:

function loca = wm_type_1(loca,w,step,g)
% 此函数用于在HL子带嵌入水印
% 输入：loca为要嵌入水印的子带
% 输出：loca为嵌入水印后的子带

[m2,n2] = size(loca);
index = 1;
% 取出2*2的块
for k = 1:2:m2-1
    for kk = 1:2:n2-1
        tem = loca(k:k+1,kk:kk+1);
        a11 = tem(1,1);
        a12 = tem(1,2);
        a21 = tem(2,1);
        a22 = tem(2,2);
        if 0 == w(index)
            for s = step:step:100*step
                if a21-a11<=g   % 如果满足条件，a21增，a22减
                    a21 = a21 + s;
                    a22 = a22 - s;
                else
                    break;     % 不满足条件，跳出此循环
                end
            end
            %-----如果a12和a22不满足条件，则也要调整------------
            if a12-a22<=g
                a12 = a12 + s;
                a22 = a22 - s;
            end
            tem(1,1) = a11;
            tem(1,2) = a12;
            tem(2,1) = a21;
            tem(2,2) = a22;
            loca(k:k+1,kk:kk+1) = tem;
            
        end
        if 1 == w(index)
            for s = step:step:100*step
                if a21-a11>=-g   % 如果满足条件，a21减，a22增
                    a21 = a21 - s;
                    a22 = a22 + s;
                else
                    break;     % 不满足条件，跳出此循环
                end
            end
            %-----如果a12和a22不满足条件，则也要调整------------
            if a12-a22<=g
                a12 = a12 + s;
                a22 = a22 - s;
            end
            tem(1,1) = a11;
            tem(1,2) = a12;
            tem(2,1) = a21;
            tem(2,2) = a22;
            loca(k:k+1,kk:kk+1) = tem;
            
            
            
        end
        index = index + 1;
        tem(1,1) = a11;
        tem(1,2) = a12;
        tem(2,1) = a21;
        tem(2,2) = a22;
        loca(k:k+1,kk:kk+1) = tem;
    end
end