Robust and Imperceptible Watermarking Techniques for Multimedia Data

Abstract

In today’s modern world, it is easily accessible to replicate and broadcast digital content through the Internet. There are three different modes to shield multimedia contents such as steganography, cryptography and watermarking. Among them watermarking is the most popular technique and holds excessive ability. Digital watermarking gained wide interest in the field of multimedia objects. Digital watermarking systems are implemented to assure data authentication, copyright protection in multimedia data transmission. Moreover, it guarantees to shield the digital media from malicious attacks, piracy, interfering, and distribution of information. Digital watermarking is broadly pre-owned as a robust technique for enhancing trust in the distribution of multimedia contents. In this thesis, transform-domain-based robust, secure and imperceptible watermarking schemes are presented using encryption and optimization techniques for color images. A new watermarking and encryption results are defined based on these methods. The main purpose of this work is to increase the robustness, imperceptibility, security, and embedding capacity of multimedia data. The first objective is implemented to achieve a secure and robust watermarking system for color images. The purpose of the second objective is to boost the robustness without damaging the image quality of the signed images. In the third objective security, embedding capacity, and robustness are improved with the wavelet fusion method. In the last objective, multiple watermarking based on transform-domain techniques is implemented to attain imperceptibility and robustness. These four objectives are also capable of resisting some image processing attacks. The proposed techniques achieve good performance in terms of Peak Signal-to-Noise Ratio (PSNR), Normalized Correlation (NC), Number of Changing Pixel Rate (NPCR), and Unified Average Changed Intensity (UACI) and found to be better when compared with previous approaches.