Research On Reversible Information Hiding Algorithm For JPEG Images

With the rapid development of computer and internet application technology,digital media has been increasingly widely and deeply used.These digital media transmitted through the open network is vulnerable to illegal interception,tampering and attack.How to ensure the information security has become a concern of the whole society.In order to meet the challenge of information security,more and more researchers pay attention to information hiding technology.When the traditional information hiding technology embeds the secret information into the carrier object,it will cause irreversible distortion to the original carrier,so that the original carrier can not be completely restored.Reversible information hiding technology can not only extract the hidden secret information,but also reconstruct the original information carrier completely.This technology is mainly used in legal evidence collection,military communication,medical image,copyright protection and other applications where the carrier object does not allow distortion.At present,JPEG image as a digital image format has been used widely.It is very important to study reversible information hiding based on JPEG image to protect information security.This paper focuses on the latest research of reversible information hiding technology,and mainly carries out the following work:1.An improved reversible information hiding algorithm of JPEG image based on the histogram shift(HS)of quantized DCT coefficients is proposed.The new algorithm includes the improved DCT block selection method and the frequency selection method.Based on the analysis of the relationship between the value of the quantization table,the distribution of the quantization AC coefficient and the embedding distortion of JPEG image,then according to the AC coefficient satisfying the Laplace distribution characteristics,the estimation model of coefficient distribution is established.Finally,according to the estimation model,the block selection method based on the estimation distortion and the frequency selection method based on the embedding efficiency are proposed.2.Based on the analysis of the principle of compression and coding of color JPEG image and the distribution characteristics of DCT coefficients,a reversible information hiding strategy of color JPEG image is proposed.Through the combination of theoretical analysis and experimental research,with different color components of color JPEG images,the distribution characteristics and embedding performance of quantized DCT coefficients are analyzed and compared.The influence of quantization step and down sampling of chroma components on embedding performance is analyzed,and then a reversible information hiding scheme suitable for color JPEG images is proposed.3.With the most advanced algorithm of reversible information hiding of JPEG image,the proposed method of this paper is analyzed and compared.For evaluating the embedding performance of various algorithms,some evaluation criteria include the embedding capacity,visual quality and image file size increment are used.Compared with the current advanced algorithm,the experimental results show that the new scheme can improve the visual quality of image and reduce the increment of file size effectively,this proves our algorithm has more advantages.