Nowadays, audiovisual content is distributed rapidly but also extensively to remote regions via the web in a number of formats, comprising images, audio, video, and textual. Everything is easily accessible and simple for all users thanks to digitized transmission via the World Wide Web. As a consequence, data protection is indeed a required and essential activity. Confidentiality refers to content that is secure yet not accessed by unauthorized individuals. Information security is insufficient on its own to assure the constant operation of data such as text, audio, video, and electronic images. Although there are several ways to image security available, including encryption, watermarking, digital watermarking, reversible watermarking, cryptography, and steganography. The goal of this book is to transfer secure textual data storage on public networks and IoT devices by concealing secret data in multimedia. It also covers discussions on textual image recognition using machine learning/deep learning-based methods. This book also offers advanced steganography ways for embedding textual data on the cover image, as well as a new way for secure transmission of biological imaging, imaging with machine learning and deep learning, and 2D, 3D imaging in the field of telemedicine.