A New Watermarking and Information Hiding Technique Based on Discrete Wavelet Transform

This paper presented a new watermarking method for convert communication and copyright protection. For improving the transparency and robustness of watermarking or information hiding, a visual model was employed to calculate the block based just noticeable difference (JND), and the three detail sub-bands of block discrete wavelet transform (DWT) were selected for embedding objects. Firstly, a watermark sequence binarized from a text information file or image file was encoded by redundant encoding and scrambled chaotically. Then, an image block was selected each time from the carrier image, and transformed by DWT. And then according to the JND and the watermark code, the coefficients at same position of three detail sub-bands were adjusted to hide the information. Lastly, the inverse DWT was executed to get the information hidden image. The experimental results show that the hidden information is invisible, and the algorithm is robust to general image processing operations. The conclusion is that the algorithm is effective and practical.