仿真代码之三

部分仿真代码，供参考
 
  


  %
  designed by lilizong
  %
  lilizong[at]gmail


a
  =
  imread(
  '
  c:bbb.png
  '
  );   
  %
   读入图像
figure,imshow(a),title(
  '
  原图像
  '
  );  
  %
  显示图像
figure,imhist(a);
b
  =
  a(:);
[m,n]
  =
  size(a);
k
  =
  size(b);
  %
    下述操作可以实现像素的显示
c
  =
  linspace(
  0
  ,
  0
  ,
  256
  );
  for
   i
  =
  1
  :k
    
  for
   j
  =
  1
  :
  256
  
        
  if
  (b(i)
  ==
  j)
            c(j)
  =
  c(j)
  +
  1
  ;
        end
    end
end
  %
    以下步骤简单实现读取整个图像的峰值点

max
  =
  c(
  1
  );
maxi
  =
  0
  ;
  for
   i
  =
  1
  :
  256
  
    
  if
  (c(i)
  >
  max)
        max
  =
  c(i);
        maxi
  =
  i;
    end
end
max
maxi




  %
    下面步骤实现对各个峰值的读取
d
  =
  c;  
  %
  作为临时操作数组，以不破坏原数组
emax
  =
  linspace(
  0
  ,
  0
  ,
  256
  );
emaxi
  =
  linspace(
  0
  ,
  0
  ,
  256
  );
a
  =
  1
  ;
  for
   j
  =
  2
  :
  256
  
    
  if
  (d(j)
  >
  d(j
  -
  1
  ) 
  &
  d(j)
  >
  d(j
  +
  1
  ) 
  &
  d(j)
  ~=
  8888
  )
        emax(a)
  =
  d(j);
        emaxi(a)
  =
  j;
        d(j)
  =
  8888
  ;
        a
  =
  a
  +
  1
  ;   
  %
  开始没有想明白，用额外的循环变量
    end
end


  %
    下面的程序读取四个高峰值，并进行显示
fmax
  =
  linspace(
  0
  ,
  0
  ,
  10
  );
fmaxi
  =
  linspace(
  0
  ,
  0
  ,
  10
  );
bnum
  =
  1
  ;
  for
   i
  =
  1
  :
  10
  
    fmax(bnum)
  =
  emax(
  1
  );
    
  for
   j
  =
  2
  :
  256
  
        
  if
  (emax(j)
  >
  fmax(bnum))
            fmax(bnum)
  =
  emax(j);
            fmaxi(bnum)
  =
  emaxi(j);
            t
  =
  j;
        end
    end
    emax(t)
  =
  0
  ;
    bnum
  =
  bnum
  +
  1
  ;
end


  for
   i
  =
  1
  :
  10
  
    fmax(i)
    fmaxi(i)
end

  %
    至此峰值已经提出出来了







  %
  在第一个峰值嵌入水印
  %
    首先把小于最大的像素值的都减去2
cc
  =
  zeros(m,n);
c
  =
  cc(:);

  for
   i
  =
  1
  :k
    
  if
  (b(i)
  <
  fmax(
  1
  ))
        c(i)
  =
  b(i)
  -
  2
  ;
    end
end

watermark
  =
  imread(
  '
  c:watermark.png
  '
  );
figure,imshow(watermark);
[w1,w2]
  =
  size(watermark);
watermark_line
  =
  watermark(:);
oo
  =
  w1
  *
  w2;

  %
  开始嵌入水印

  %
  第一次水印

tt
  =
  1
  ;  
  %
  让tt加1来遍历整个水印图像
  for
   i
  =
  1
  :k
    
  if
  (c(i)
  ==
  fmax(
  1
  ))
        
  if
  (tt
  >
  oo)
            tt
  =
  1
  ;  
  %
  如果超出水印的范围从头开始
            
  if
  (watermark_line(tt)
  ==
  1
  )
                c(i)
  =
  c(i)
  -
  1
  ;
            end

        end
        tt
  =
  tt
  +
  1
  ;
    end
end



  %
  第二次水印
tt
  =
  1
  ;  
  %
  让tt加1来遍历整个水印图像
  for
   i
  =
  1
  :k
    
  if
  (c(i)
  ==
  fmax(
  2
  ))
        
  if
  (tt
  >
  oo)
            tt
  =
  1
  ;  
  %
  如果超出水印的范围从头开始
            
  if
  (watermark_line(tt)
  ==
  1
  )
                c(i)
  =
  c(i)
  -
  2
  ;
            end
        end
        tt
  =
  tt
  +
  1
  ;
    elseif(c(i)
  ==
  fmax(
  2
  )
  +
  1
  )
        
  if
  (tt
  >
  oo)
            tt
  =
  1
  ;
            
  if
  (watermar_line(tt)
  ==
  1
  )
                c(i)
  =
  c(i)
  -
  2
  ;
            end
        end
    end
end









  %
  显示嵌入水印的图像


embed
  =
  c;
embed
  =
  reshape(c,m,n);
figure,imshow(embed,[]),title(
  '
  嵌入水印的图像
  '
  );


  %
  提取水印

  %
  提取第一层

  for
   i
  =
  1
  :k
    
  if
  (c(i)
  ==
  fmax(
  2
  ))
        watermark(tt)
  =
  0
  ;
        
  %
    tt
  =
  tt
  +
  1
  ;
        
  %
  elseif(c(i)
  ==
  (fmax(
  1
  )
  +
  1
  ))
        
  %
     watermark(tt)
  =
  0
  ;
        
  %
    tt
  =
  tt
  +
  1
  ;
        
  %
  elseif(c(i)
  =
  fmax(
  1
  )
  -
  1
  )
        
  %
      elseif(c(i)
  =
  fmax(
  1
  )
  -
  1
  )
        
  %
         watermark(tt)
  =
  1
  ;
        
  %
        tt
  =
  tt
  +
  1
  ;
        
  %
   elseif(c(i)
  =
  fmax(
  1
  )
  -
  2
  )
        
  %
      watermark(tt)
  =
  1
  ;
        
  %
     tt
  =
  tt
  +
  1
  ;
        
  %
  end
    
  else
  
        
  if
  (c(i)
  ==
  fmax(
  2
  )
  +
  1
  )
            watermark(tt)
  =
  0
  ;
        
  else
  
            
  if
  (c(i)
  ==
  fmax(
  2
  )
  -
  1
  )
                watermark(tt)
  =
  1
  ;
            
  else
  
                
  if
  (c(i)
  ==
  fmax(
  2
  )
  -
  2
  )
                    watermark
  =
  1
  ;
                end
            end
        end
        tt
  =
  tt
  +
  1
  ;
    end
end


  %
  提取第二层


  for
   i
  =
  1
  :k
    
  if
  (c(i)
  ==
  fmax(
  1
  ))
        watermark(tt)
  =
  0
  ;
        tt
  =
  tt
  +
  1
  ;
    elseif(c(i)
  ==
  (fmax(
  1
  )
  -
  1
  ))
        watermark(tt)
  =
  1
  ;
        tt
  =
  tt
  +
  1
  ;
    end
end
  for
   i
  =
  1
  :oo
    watermark_dect(i)
  =
  watermark(i);
end











  for
   i
  =
  1
  :oo
    watermark_dect(i)
  =
  watermark(i);
end
watermark_dect
  =
  reshape(watermark_dect,w1,w2);
figure,imshow(watermark_dect,[]),title(
  '
  提取出来的水印
  '
  );


  %
  恢复原图像
dd
  =
  embed(:);
  for
   i
  =
  1
  :k
    
  if
  (c(i)
  ==
  (max
  -
  2
  ))
        c(i)
  =
  c(i)
  +
  2
  ;
    elseif(c(i)
  <
  max
  -
  2
  )
        c(i)
  =
  c(i)
  +
  2
  ;
    end
end
dd
  =
  reshape(c,m,n);
figure,imshow(dd,[]),title(
  '
  恢复的图像
  '
  );



a
  =
  imread(
  '
  c:bbb.png
  '
  );

x
  =
  a;
x1
  =
  embed;
x
  =
  double
  (x);
x1
  =
  double
  (x1);
  for
   i
  =
  1
  :
  256
  ;
    
  for
   j
  =
  1
  :
  256
  ;
        MYa(i,j)
  =
  x(i,j)
  ^
  2
  ;  
  %
  after filtering
  '
  s single
  
          MYb(i,j)
  =
  x(i,j)
  -
  x1(i,j);
    end
end
d
  =
  0
  ;
e
  =
  0
  ;
  for
   i
  =
  1
  :
  256
  ;
    
  for
   j
  =
  1
  :
  256
  ;
        d
  =
  d
  +
  MYa(i,j);
        e
  =
  e
  +
  MYb(i,j)
  *
  MYb(i,j);
    end
end
f
  =
  log10(d
  /
  e);
g
  =
  10
  *
  f