Continuous Wavelet Transform Applications In Steganography

Abstract

Steganography is the art of hiding confidential information. The main purpose of steganography is to hide a message and to make it invisible for an attacker even in the case of receiving an object where the message was hidden. Messages can be, for example, hidden in audio or video signals.Steganography methods can be divided into spatial and frequency. The first group of methods directly changes the components of the original image (pixels), therefore, they visually reduce the quality of the image. One of the most well-known and widespread methods is a discrete cosine transform (DCT). As an alternative to DCT, discrete wavelet transform (DWT) is increasingly being used. Wavelet transform is a relatively new concept. There is a trend towards using wavelets in signal processing and analysis instead of or in addition to discrete cosine transform (DCT).One of the applications of steganography in an image is the use of a watermark. The purpose of a digital watermark is to hide the watermark (a kind of identification data) inside the image so that it is not perceptible to the human eye, but also so that it is stable enough to withstand various kinds of transformations.This paper is focusing on successfully hiding information in an image with the help of a wavelet transform without a visible change to the source file. The proposed algorithm includes a single-level 2D wavelet transform based on various types of transformations such as Haara, Daubeshi and Coiflet.