Securing Digital Photography Images by Encryption-Watermarking CFA (Color Filter Array) Images

Introduction

Today's digital networks are so highly developed that they have become an essential communication medium. They enable the transmission of all kinds of information: text, sound and above all, images. The increased use of the latter is reinforced by the emergence of cameras, digital cameras, cell phones, scanners and IRM.

The rapid development of communication technologies and image-processing tools raises a number of important issues: illegal distribution, duplication, falsification, confidentiality and so on. Authors and providers of multimedia data are reluctant to allow their data to be distributed in a networked environment because they fear unrestricted duplication and dissemination of copyrighted material.

These problems have prompted a number of researchers to take an interest in securing digital data through various protection techniques such as steganography, encryption, watermarking and even encryption-watermarking. The hybrid method of encryption-watermarking is the one we'll be studying in our work with a view to i) ensuring the secure transfer of digital photographic images ii) achieving a better compromise between invulnerability (robustness and security) and the amount of information to be embedded (capacity and imperceptibility).

To meet these needs, a new line of research is rapidly developing: hybrid encryption-watermarking algorithms. In this work, our contribution is to propose three robust hybrid algorithms combining chaotic encryption and blind watermarking of CFA images based on the quaternionic wavelet transform (QWT) to solve the various problems posed in our approach.