The rapid growth of the Internet has fueled the demand for enhanced watermarking and data hiding technologies and has stimulated research into new ways to implement watermarking systems in the real world. This book presents the fundamental principles of watermarking system design and discusses state-of-the-art technologies in information concealment and recovery. It highlights the requirements and challenges of applications in security, image/video indexing, hidden communications, image captioning, and transmission error recovery and concealment. It explains the foundations of digital watermarking technologies, and offers an understanding of new approaches and applications, and lays the groundwork for future developments in the field.