Research On Reversible Data Hiding Of JPEG Image Based On Distortion-extension Cost

With the development of Internet and communication technology,digital image has become one of the main multimedia information carriers in Internet transmission because of its what you see is what you get,intuitive and efficient characteristics.Taking digital image as a carrier,the security of digital image can be effectively improved by reversible data hiding(RDH)technology.JPEG image is one of the most widely used image formats in the Internet,and reversible data hiding technology based on JPEG image has become a research hotspot of image security technology.This thesis design two reversible data hiding algorithms based on JPEG image by histogram shifting data embedding method,combining embedding frequency selection strategy and embedded image block selection strategy,focuses on three main performance indicators: embedded capacity,visual quality and the increase of file size of the marked images.Firstly,a reversible data hiding algorithm of JPEG images based on distortion-extension cost is designed.The proposed algorithm takes into account both the increase of file size and the visual distortion of the marked JPEG image,focusing on how to adaptively select embedding frequency and image block according to embedding capacity,so as to minimize the visual distortion and the increase of file size of the marked JPEG image.In the frequency selection strategy,the unit simulation file increment of different frequencies is calculated from the cost of image file expansion,and the frequency with smaller unit simulation file increment is preferred to embed data;when selecting embedded blocks,the number of zero alternating current coefficients in each block is sorted.When the number of zero alternating current coefficients of image blocks is the same,the smoothness of blocks is calculated and reordered,when embedding data,the smooth blocks are selected first.Experimental results demonstrate that compared with the latest similar algorithms,the proposed algorithm can achieve a better balance between the increase of file size of the marked JPEG image and visual quality,and reduce the increase of file size of the marked JPEG image,and the average of unit file increment under the same embed capacity has been reduced by0.15?0.25.Secondly,a reversible data hiding algorithm for JPEG image based on embedding efficiency and simulation distortion is designed.In the frequency selection strategy,based on the idea of distortion-extension cost,the distortion-extension cost normalization model is established,and the embedding efficiency of different frequencies is calculated by changing the weight factor,so as to adjust the preference of visual quality and the increase of file size according to the actual needs.When embedding data,the frequency with higher embedding efficiency is preferred,and the proposed algorithm has higher flexibility.In addition,in order to calculate the simulation distortion more accurately,Laplace distribution is introduced as the mathematical model of DCT coefficient distribution,and the block with smaller simulation distortion is preferred.Experimental results demonstrate that the proposed algorithm can control the increase of file size of the marked JPEG image to a minimum while ensuring the visual quality of the marked JPEG image,and the algorithm is more flexible.