Research On Information Hiding And Analysis Technology Based On Images

In recent decades, with the booming growth of wireless network and worldwide telecommunication, people tend to become more and more reliant on Internet. However, it will result in some potential problems generated by digitalized data without the assurance of security and protection of confidentiality. The information security has become an increasingly important issue to be protected against illegal three-party access. Data hiding has become a hot topic in the digital era to ensure the safety of digital information. It has won popularity in terms of imperceptibility, undetectability and invisibility. It is treated as embedding data or watermarking into a host or cover media such as texts, images, videos and so on. Many stenographic methods were proposed by scholars recently. However, these methods are still need to be optimized in terms of embedding capacity, imperceptibility and cost. Accordingly, some research works are presented in this thesis.1. A novel steganography approaches based on combination of LSB replacement mechanism and edge detection is proposed. To avoid excavation of human visual system(HVS) when more secret bits are embedded into pixels, we classify the cover pixels into edge pixels and non-edge pixels. Then, embed more secret bits into the edge pixels than the non-edge pixels based on the LSB substitution scheme. In addition, to further increase the payload as well as preserve good image quality, we adopt a skillful way that the edge information is determined by the most significant bits(MSBs) of the cover image so that it does not need to be stored. The experimental results show that the proposed scheme not only achieves high embedding capacity but also enhances the quality of the stego image from the HVS by an edge detection technique.2. A high payload stenographic scheme for compressed images with Hamming Code is proposed. It inserts secret message into the AMBTC compressed bit-stream. The scheme exploits the matrix embedding algorithm which is favored by its high embedding efficiency to improve the visual quality of stereographic image. Additionally, the relationship between the low and high means is judged whether to conceal confidential information into the corresponding compressed block or not. Experimental results demonstrate that our scheme outperforms the other existing data hiding approaches for compressed images in terms of embedding capacity, bit rate, and hiding efficiency.3.A reversible hiding scheme using ordered cluster-Based VQ Index Tables is proposed. It can reduce the use of overhead bits, which is especially effective for images of complex texture. Specifically, a codebook is partitioned into six clusters which are organized based on the usage frequency of codewords. We then develop a new mapping relationship among the six clusters to hide secret data more cost-effectively. The experimental results demonstrate that the proposed scheme outperforms other schemes in terms of cost and embedding capacity.