A NOVEL DESCENT TECHNIQUE FOR DIGITAL IMAGES STEGANOGRAPHY BASED ON MODIFIED DISCRETE COSINE TRANSFORM & HUFFMAN CODING

Abstract

In the recent years image steganography techniques can be divided into two groups: those in the Image
Domain and those in the Transform Domain. Image – also known as spatial – domain techniques embed messages in the
intensity of the pixels directly, while for transform – also known as frequency – domain, images are first transformed and
then the message is embedded in the image.
Image domain techniques encompass bit-wise methods that apply bit insertion and noise manipulation and are
sometimes characterized as ―simple systems‖. The image formats that are most suitable for image domain
steganography are lossless and the techniques are typically dependent on the image format.