Privacy and Copyright protection is a very important issue in our digital society, where a very large amount of multimedia data are generated and distributed daily using different kinds of consumer electronic devices and very popular communication channels, such as the Web and social networks. This book introduces state-of-the-art technology on data hiding and copyright protection of digital images, and offers a solid basis for future study and research. Steganographic technique overcomes the traditional cryptographic approach, providing new solutions for secure data transmission without raising users' malicious intention. In steganography, some secret information can be inserted into the original data in imperceptible and efficient ways to avoid distortion of the image, and enhance the embedding capacity, respectively. Digital watermarking also adopts data hiding techniques for copyright protection and tampering verification of multimedia data. In watermarking, an illegitimate copy can be recognised by testing the presence of a valid watermark and a dispute on the ownership of the image resolved. Different kinds of steganographic and watermarking techniques, providing different features and diverse characteristics, have been presented in this book. This book provides a reference for theoretical problems as well as practical solutions and applications for steganography and watermarking techniques. In particular, both the academic community (graduate student, post-doc and faculty) in Electrical Engineering, Computer Science, and Applied Mathematics; and the industrial community (engineers, engineering managers, programmers, research lab staff and managers, security managers) will find this book interesting.