Steganography using dual tree complex wavelet transform with LSB indicator technique

Abstract

Image steganography is undoubtedly significant in the field of secure multimedia communication. The undetectability and high payload capacity are two of the important characteristics of any form of steganography. In this paper, the level of image security is improved by combining the steganography and cryptography techniques in order to produce the secured image. The proposed method depends on using LSBs as an indicator for hiding encrypted bits in dual tree complex wavelet coefficient DT-CWT. The cover image is divided into non overlapping blocks of size (3*3). After that, a Key is produced by extracting the center pixel (pc) from each block to encrypt each character in the secret text. The cover image is converted using DT-CWT, then the produced key is used to determine the starting pixel in each block for hiding and the direction of hiding (clockwise or anticlockwise). The proposed method is applied on many images with different embedding rate, and many metrics are used to evaluate the performance of the proposed method such as Peak Signal to Noise Ratio (PSNR), Mean Square Error (MSE), correlation factor (CF) and Structural Similarity Index Measure (SSIM). It achieves in average 52.225 dB of PSNR, 0.3215 of MSE, 0.9952 of SSIM and 0.9997 of CF with embedding rate 1.5.