A New Watermarking Technique For Multimedia Protection

A New Watermarking Technique for Multimedia Protection  Chun-Shien Lu, Shih-Kun Huang, Chwen-Jye Sze, and Hong-Yuan Mark Liao Institute of Information Science, Academia Sinica, Taipei, Taiwan. E-mail: flcs, [email protected] Abstract A robust watermarking scheme for hiding binary or gray-scale watermarks in digital images is proposed in this chapter. Motivated by the fact that a detector response (a correlation value) only provides a soft evidence for convincing jury in courtroom, embedded watermarks are designed to be visually recognizable after retrieval. To strengthen the existence con dence of a watermark, visually signi cant transformed components are selected. In addition, a relocation technique is presented to tackle geometric-distortion-based attacks without using any registration scheme. Finally, a semi-public watermark detector which does not require use of the original source is proposed for the purpose of authentication. Experimental results demonstrate that our approach satis es the common requirements of image watermarking, and that the performance is superb. Keywords: Human visual system Wavelet transform Watermarking Modulation Attacks  Corresponding author 1 1 INTRODUCTION 1.1 WATERMARKING Owing to the popularity of the Internet, the use and transfer of digitized media are increasing. However, this frequent use of Internet has created the need for security. Therefore, it is imperative to protect information to prevent intentional or unwitting use of information belonging rightful owners. A commonly used method is to insert watermarks into original information to declare rightful ownership. This is the so-called watermarking technique. A watermark can be a visible or invisible text, binary stream, audio, image or video. It is embedded in an original source and is expected to tolerate attacks of any kind. A valid watermarking procedure enables one to judge the owner of media contents via a retrieved watermark even if it is attacked and is, thus, fragmentary. An eective watermarking procedure should satisfy or consider the following requirements: 1. Transparency: The inserted watermark should be perceptually invisible. This demand is most challenging for images with large homogeneous areas. 2. Robustness: A secure watermark should be dicult to remove or destroy, or at least the watermarked image must be severely degraded before the watermark is lost. Typical intentional or unwitting attacks include:  Common digital processing: A watermark should survive after image blurring, compression, dithering, printing and scanning, etc.  Subterfuge attacks (collusion and forgery) [4]: A watermark should be resistant to combinations of the same image watermarked with dierent watermarks (collusion). In addition, a watermark should be robust to repeatedly watermarking (forgery).  Geometric distortions: A watermark should be able to survive attacks which use general geometric transformation, such as cropping, rotation, translation, and scaling. 3. Capacity: Capacity [23, 27] is the issue allowing to embed the maximum number of distinguishable watermarks. Cox et al. [4] discovered that the signi cant components of an image have a perceptual capacity that allows watermark insertion without perceptual degradation. In other words, any attack trying to remove or destroy embedded watermarks will in uence the signi cant components of an image and thus lead to delity degradation. 2 4. Public watermarking: Authentication without using original sources is necessary to two reasons [35]: (1) searching for the original image in large digital libraries is time-consuming; (2) application of \web-crawling" detection. Source-bas