Adaptive Watermarking Scheme Using Biased Shift of Quantization Index

Algorithm 1

Rearrangement algorithm for watermark data

Procedure {Watermark_Mix }

input: 2^𝑚×2^𝑛  original 2D watermark (𝑤(𝑖,𝑗))

   𝐿𝐹𝑆𝑅=(𝑧_{𝑚+𝑛−1}, 𝑧_{𝑚+𝑛−2}, …, 𝑧₁, 𝑧₀)

output: 2^𝑚×2^𝑛  rearranged 2D watermark (𝑤^(𝑖,𝑗))

begin {

 𝑘=1;

 for   𝑖=0  to  2^𝑚−1{

  for   𝑗=0  to  2^𝑛−1

   𝑤(𝑘++)=(𝑤(𝑖,𝑗));}

 initialize LFSR with key (key_LFSR);

 𝑤^(0,0)=𝑤(0);

 for  𝐼=1  to  2^𝑚+𝑛−1{

  apply one clock to LFSR;

  𝑥_𝑖=𝑧_{𝑚+𝑛−1}2^𝑚−1+𝑧_{𝑚+𝑛−2}2^𝑚−2+⋯+𝑧_𝑛+12¹+𝑧_𝑛2⁰;

  𝑦_𝑖=𝑧_𝑛−12^𝑛−1+𝑧_𝑛−22^𝑛−2+⋯+𝑧₁2¹+𝑧₀2⁰;

  𝑤^(𝑥_𝑖,𝑦_𝑖)=𝑤(𝑖);}}

end {Watermark_Mix }