Research On Steganography Algorithm With High Capacity Based On Digital Images

With the arrival of the information era, information security has become the focus of increasingconcern. The information hiding technology is an novel technology in the field of information security,more and more attention has been paid by researchers at home and abroad，and has become a hotspot ofacademic research. Steganography is an important branch of information hiding technology; it embedssecret information to the redundant data of carrier in order not to arouse suspicion and passed secretinformation in an open way. In this paper, steganography algorithm with high capacity based on digitalimage is studied, the existing steganography algorithm proposed improvements under the premise of imagequality assurance to improve the capacity of the secret information embedding.This paper mainly divided into the following three aspects:(1) Steganography algorithm based on diamond encoding (Diamond Encoding, DE) is analyzed, andthe DE algorithm is improved by proposing three-dimensional diamond encoding based on three pixels. Inthis algorithm, three pixels as an embedded unit instead of two pixels, which can increase the variablenumber of pixels and reduce the amount of change for each pixel, consequently the deterioration of theimage quality can be reduced. Experimental results show that the algorithm has better imperceptibility, andat the same PSNR premise that the algorithm can be embedded more secret information than DE algorithm.(2) The steganography algorithm based on DCT domain has small capacity, in order to solve thisproblem, a steganography algorithm based on3D_DE and quantization table modification is proposed,which effectively improved the number of the embedding location by making use of quantization tablemodification technology, while can embed more secret information with less amount of change by takingadvantage of the proposed3D_DE algorithm. Experimental results show that the algorithm under thepremise of compliance with JPEG compression standard, effectively improve the embedding capacity, hassome practical value.(3) Characteristics of human visual perception is studied and analyzed, and a steganography algorithmbase on HVS and improved diamond encoding is proposed. The algorithm embeds more secret informationin not visually sensitive areas of image and less secret information in visually sensitive areas of image bymaking use improved diamond encoding. Experimental results show that the algorithm not only has betterimage quality, but also effectively improve the embedding capacity; while also effective against RSsteganalysis.