Digital Watermarking Technique Based On Wavelet Analysis

With the booming development of multimedia technology and the exceptional growing of Internet ,we can get digital information conveniently and quickly.But how can we protect the author's copyright and economic profits?It has become much urgent to provide efficient copyright and security protection means for the digital products.So the digital watermark technology has been put forward in recent years.Digital watermark is a new direction in the information security field.It's a new technology which can protect copyright and authentication source .The author's personal copyright information can be embedded in the products.But we can't percept it ,only special software can pick it up.In this dissertation,the application of digital watermark technology has been studied in the round.First,this thesis analyzed the current development status ,basic characters and problems of digital watermark technology,and discuss the general frame of digital watermark processing system.Secondly,analyzed and implement a spatial domain LSB algorithm,although this algorithm' robustness is not good,but it is important in the secret communication.Then put forward a improved algorithm based on DCT domain,the improved algorithm have little effect to the original image ,and have good robustness.Finally,studied the embedded zero wavelet tree algorithm,and propose a new algorithm.the algorithm search the significant coefficient and embedded the watermark,this method have better robustness and is compatible with JPEG2000,the watermark dection don't need the original image.Experiments results shows that this algorithm can against widely varying signal distortions,have good robustness.