Multiple-Watermarking Scheme For Digital Image Based On ICA And DWT

With the development of internet multimedia technology, digital watermark had been the focus in the copyright protection field. It protects the ownership of multimedia data through embedding copyright information. And it is transparent and robust to resist to kinds of operation on the multimedia data.This paper introduces two multiple digital watermark schemes based on the ICA (Independent Component Analysis), DWT (Discrete Wavelet Transform) and Hash replacement. In this paper we adopt static digital image watermark as research object. The background and development status of the digital watermark technology are also presented simply.In the first chapter, we introduce the digital watermark technology summarily, including its background, basic framework and guidelines of the performance evaluation. At the same time the application and study status of the digital watermark are presenting.The second chapter gives us the preparative knowledge of the multiple digital watermark algorithms. The Hash replacement, DWT and ICA technology are introduced detailed. Especially the FastICA algorithm of ICA technology, we introduced weightily. At the same time, other investigators' work is also presented.The third and forth chapters are the important part of the paper. In this part, two algorithms are introduced in detail. The material content is showed as follows.(1) The multiple digital watermarking scheme based on DWT and ICA. Firstly, DWT was applied to one sub-image extracted from the original image orderly, at the same time, the multiple independent watermark signals mixed with ICA and generated mixed signals. Then a signal was chosen from the mixed signals as watermarking embedding into the intermediate frequency by mixing with ICA. At the extracting stage, using the same rule as embedding stage, extracting the sub-image from watermarked image, then every embedded watermark signals can be extracted through twice demixed with ICA by inverse embedding process. Using the watermarking standard testing tool Stirmark to attack the watermarked images, the simulation results demonstrate the novel approach's good performance of the robustness and invisibility.(2) A multi-digital watermark scheme is proposed based on image independent feature. The independent component analysis (ICA) technology is applied to gain the independent feature of image firstly. Then the independent features are decomposed by discrete wavelet transform (DWT). At last, the encrypted watermarks which are transformed by Hash replacement are embedded into the low-frequency sub-band. Simulation results show that the proposed scheme is transparent as well as improve the information rate, at the same time, it is robust against common attacks, such as adding noise, JPEG compress, rote and cropping, etc, and also solves the problem of multi-copyright in digital products.The last chapter compares the above schemes presented in this paper. At last, the work of the paper is concluded and the next study is prospected.