Data Hiding in Digital Multimedia

Abstract

Digital watermarking and data hiding, schemes to embed secondary data in digital media, have made considerable progress in recent years and attracted attention from both academia and industry as a security tool. Data hiding is also found useful as a general tool to send side information in multimedia communication for achieving ad­ ditional functionalities or enhancing performance.

Imperceptibility, robustness against moderate processing such as compressiOn, and the ability to hide many bits are the basic but rather conflicting requirements for many data hiding applications.

The work included in this thesis aims to develops a data hiding technique, which uses the information theory to surmount the problem of uneven embedding (all im­ age's regions have not the same ability to contain the same amount of side informa­ tion). Whereas, the image features are studied and the amount of information that can be embedded in each region will be determined by the amount of information con­ tained in this region. Thereby the quality of used images was maintained with embed­ ding a large amount of side data.

Additionally, the proposed technique uses a security system that depends on using secret keys and generating quasi-random distribution that applied to the messages dur­ ing the hiding process which achieves more security and make the proposed technique follows the secure steganographic model.

Finally, the proposed technique is enhanced using slightly more computation; whereas the message is compressed before it is embedded that gives the ability to em­ bed a large amount of data while keeping the quality of the used images and the re­ covered messages. The experimental results of applying this technique to several im­ ages and text messages shows its ability to embed a large amount of data- with image