An Improved Image Steganography Scheme Based on RDWT and QR Decomposition

Abstract

This paper demonstrates an improved image steganography that hides grayscale secret image into grayscale cover image using RDWT and QR decomposition. The proposed scheme made use of the human visual system in the information hiding process. Both cover and secret image are being divided into non-overlapping image blocks with identical block size. Entropy values generated from every image block will be sorted from the lowest value to the highest value. The embedding process starts by embedding the secret image block with lowest entropy value into the cover image block with lowest entropy value. The process goes on until all image blocks have been embedded. Embedding secret image into cover image according to the entropy values causes differences that HVS can less likely to detect because of the small changes on image texture. The proposed scheme gives higher PSNR values and better image quality.