Research On Robust Image Digital Watermarking Algorithm And Protocols

Recently, the development of multimedia and Wide Band technology promote the development of the digital media application. Many types of multimedia works such as images, music and films can be conveyed in a new way of network. One side, it brings people conveniences of intercommunion each other. On the other hand, it provides chances that the third party accesses and operates the multimedia products, for example, anybody can get the original products of others easily through the network. Someone can copy and tamper the original works arbitrarily under disagree, as infringes the author's copyright. So how to protect the multimedia products safeties is an urgent subject.Digital watermarking which is one of the important fields of information hiding has been a rising information security technology. It embeds watermarks into the multimedia products, such as still image, video, audio, text, software, then carries out the functions such as hiding transmitting, storing, data safeguarding by tracking the use of the product by detecting or extracting the watermarks. At present, digital watermarking technology has shown the vast application values in the fields of copyright protecting, copy tracing and integrity safeguarding of multimedia products.This paper introduced digital watermarking technology synoptically firstly. Then it expatiated on the basic theory and general requirements of robust digital watermarking technology which is used to protect the still image copyright. Based on the classifying analyzing of some existing typical robust watermarking algorithms and its attacks means, it pointed out two important issues in current robust image watermarking technology research. And then, an adaptive image watermark algorithm based on the energy analysis of wavelet coefficients block was proposed. Theoretical analysis and experimental results show that the proposed watermarking method is invisible and more robust against common image processing and geometrical operation. Finally, it studied the problems in buyer's right protection and copy tracing fields, and presented an interactive buyer-seller watermarking protocol based on the RSA algorithm by applying the theories and techniques of modern cryptography. Theoreticalanalysis shows that the protocol can protect the buyer's rights and the seller's profits.