Implementation of image steganography using 2-level DWT technique

Abstract

Image steganography is an engineering term defining a different and significant discipline for information hiding. This process can be described as ‘hiding of secret information behind an image’. Discrete wavelet Transform (DWT) is one of the known methods under steganography. The focus of the proposed work in this paper is on decreasing the complexity in image hiding through DWT technique while providing better undetectability and lesser distortion in the stego image. This paper proposes the algorithm for embedding and extracting the secret image embedded behind the cover gray scale image. Also, the analysis of performance measurement methods such as Peak signal to noise ratio (PSNR) and Mean square error (MSE), gives us the experimental summary for four different cases where each cases spans different sizes of cover and secret image, comparing the cover image & stego image at the sender’s side and embedded secret & extracted secret at the receiver’s side. The stego attacks are then applied on the stego image and after each of the attack, the secret image is extracted from the distorted image. For better analysis, this extracted secret is compared with the expected result on the basis of PSNR and MSE. Also, the proposed algorithm is compared with one of the existing method using DWT technique, proposed by K.B. Shiva Kumar et. al. and hence the conclusion is drawn.