Research On Color Image Compression And Encryption Algorithm Based On Fractional Hyperchaos System

In the era of mobile Internet,multimedia data such as images is a very effective way to realize information sharing.Due to the increasing amount of information carried by color images,the security and privacy protection of image information are becoming more and more important,which puts forward higher requirements for the design of efficient and secure image transmission algorithms.Image compression and encryption is an effective way to solve these two problems.Based on the above points,a color image compression and encryption scheme based on fractional hyperchaos system is proposed in this paper.In recent years,the image encryption algorithm based on chaotic system has been continuously proposed,which transits from low-dimensional mixing to high-dimensional and then to fractional chaotic system.More initial state values are used as the key of the encryption system,so as to improve the key space of the whole system.But then comes the increase of system complexity and difficult problems to solve.Fractional order chaotic system has more complex dynamic characteristics.The design of efficient compression and encryption algorithm based on fractional order chaotic system is a hot issue.Based on the above points,a color image compression and encryption scheme based on fractional hyperchaos system is proposed in this paper:1.Fractional chaotic system has better dynamic characteristics and larger key space.In this paper,fractional hyperchaotic Chen system is used as the input of encryption scheme,Adomian decomposition algorithm is used to deduce and solve in detail.Combined with DNA encoding and decoding technology,a secure color image encryption algorithm is designed.2.Both DNA encoding and decoding and DCT quantization and compression are based on block processing,which can effectively improve the parallel characteristics of the algorithm.However,the data format applicable to DNA encoding and decoding technology is generally in the form of positive integer in spatial domain,while DCT coefficients are in the form of floating point in frequency domain.The combination of DNA encoding and decoding technology and DCT quantization and compression technology leads to the problem of data format conversion.A data processing algorithm is designed,which can use DNA encoding and decoding technology to process frequency domain DCT coefficients in spatial domain.3.Considering the high efficiency of transmission,on the basis of ensuring the encryption performance,using compression algorithm,a scheme of color image compression and encryption is designed.After comprehensively analyzing the comparative experimental results of different algorithms,the data of R,G and B channels of color image are converted to frequency domain by twodimensional discrete cosine transform(DCT),and then the amount of encrypted data is reduced by quantization process.The experimental results and security analysis show that the compression encryption scheme not only has good compression and security performance,and can reconstruct the original image well under the condition of low compression ratio,but also has good robustness and security.It can be applied to the fields of color image compression,encryption and transmission.