Dct Based Image Steganographic Approach

摘要

Steganography is the art of invisible communication. Its purpose is to hide the very 8presence of communication by embedding messages into innocuous-looking cover objects. In today's digital world, invisible ink and paper have been replaced by much more versatile and practical covers for hiding messages ¨C digital documents, images, video, and audio files. As long as an electronic document contains perceptually irrelevant or redundant information, it can be used as a "cover" for hiding secret messages. Each steganographic communication system consists of an embedding algorithm and an extraction algorithm. To accommo date a secret message, the original image, also called the cover-image, is slightly modified by the embedding algorithm. As a result, the stego-image is obtained. This paper is a review of the DCT based steganography techniques appeared in the literature