Research On Encryption Methods Of Light Field Image

In recent years,with the continuous development of computers and Io T technology,the amount of information data stored is increasing.While multimedia forms such as images and videos have become indispensable in our daily lives,the privacy of personal data has become a widespread concern.Digital images as a typical representation of multimedia data,how to effectively protect image data has become a research hotspot.Digital image encryption is one of the most direct and effective ways to protect the original information of an image.The high redundancy of the image compared to textual data has led to the need for a more sensitive and stochastic approach to the characteristics of the encryption process.Unlike traditional natural images,light field images as a representation of a three-dimensional scene in space contain not only information about the direction and intensity of light during its propagation,but also more information in the angle domain.How to apply effective and applicable cryptographic models to the security of light field images is a research area worth exploring and developing.Some basic features of chaotic systems,such as extreme sensitivity to initial conditions,boundedness,internal randomness,and unpredictability.They are consistent with two basic principles of chaos and diffusion in modern cryptography.Image encryption techniques based on chaotic systems tend to be better encrypted as well as more secure than traditional techniques such as pixel placement clutter.In this thesis,we study the factors affecting the data content of light field images and the way they act,and construct an encryption algorithm applied to light field images based on the security protection of light field images.Based on the relevant research results,two light field image encryption algorithms are proposed,and theoretical introduction and experimental analysis are performed.The main research in this paper is as follows.(1)A combination of chaos theory and DNA computational cryptography is applied to the encryption of light field images.Taking into account the high dimensional nature of light field images,the spatial and angular domain representation of features that are clearly distinguished from natural images.According to the relevant theory,a secure encryption algorithm for color light field images based on DNA sequences and chaotic systems is proposed.First,a multi-view image of the light field image is represented by using the angular domain plane,andthen a single sub-view image is obtained in the spatial domain.For a given sub-view image and random matrix,a chunking method is applied to divide the sub-view image into multiple sub-blocks,which are then encrypted using a DNA sequence and chaos system.In addition,considering the relationship between the two planes in the light field,the Arnold transform is applied to all sub-view images to achieve the final encrypted cipher image.Finally,through the statistical analysis of the cryptographic algorithm,resistance attack analysis and key analysis,the experimental results show that the scheme has good applicability,reliability and security to a certain extent.(2)By analyzing the advantages of optical cryptography and considering the extremely high data redundancy of the light field image,a fast and efficient optical cryptography is applied to the data of the optical field image for encryption protection.On the basis of this,a scheme for encoding the optical field image based on pixel substitution and double random phase encoding is proposed.First,the angular plane is used to represent a multi-view image of the light field image.Pixel dislocation and diffusion processing based on rows and columns for single-view light field images to obtain intermediate images after pixel displacement.The pixel-displaced image is then processed using a Fourier transform based on double random phase encoding to obtain the final cipher image.The experimental results show that the proposed encryption model based on pixel substitution and double random phase encoding for light field images has good noise immunity and high execution efficiency,which also shows the effectiveness and suitability of the proposed encryption model for light field images.