Research On Geometric Transformation And Encryption Algorithm For Quantum Grayscale Image

In a data-intensive environment,issues such as real-time information processing and security are of great importance.Due to the limitations of traditional manufacturing technology,the performance development of conventional computers is a bottleneck.Quantum computing has unique features such as parallelism,superposition and entanglement,which greatly improve computational speed and information storage performance,and are of great research interest.As a interdiscipline between quantum computing and classical image processing,quantum image processing makes good ues of the advantages of quantum computing in every stage of image processing,which greatly enhances the performance of complex image processing tasks.The work of this paper is to further investigate the geometric tranformation and encryption algorithm for quantum grayscale image,which is based on the current mature quantum image representation models,and the main work of the research are as follows:(1)Research on geometric transformation for quantum grayscale imageGeometric transformation is inevitably required in many applications of quantum image processing which is a fundamental operation in quantum image processing.Although many quantum geometric transformation schemes have been proposed,the common problem is that the complexity of quantum circuits is too high or the number of required auxiliary qubits is too large,so more efficient geometric transformation schemes need to be further proposed.Based on flexible representation of quantum images(FRQI)and normal arbitrary superposition state(NASS),this paper proposes two geometric transformation schemes for quantum grayscale images with less complexity and fewer auxiliary qubits.Firstly,a linear cyclic translation with the complexity O(n)is implemented using auxiliary qubits,and the circuit of the linear cyclic translation on quantum grayscale images is constructed.Then,a two-point swap with the complexity O(n)is implemented on the quantum grayscale image using most one auxiliary qubit.The results of the simulation experiments show that the proposed quantum geometric transformation are superior to the corresponding operations.(2)Research on encryption algorithm for quantum grayscale imageBased on the FRQI model,an image encryption algorithm for quantum grayscale image is proposed in our research,combining the Haar wavelet transform and the block-based geometric transformation.Firstly,the block-based geometric transformation is iteratively executed in the spatial domain to scramble the coordinate information of each pixel;Secondly,based on the 1-level quantum Haar wavelet transform,the block-based geometric transformation is used again in the frequency domain to disrupt the approximate information of the quantum image.Finally,the inverse 1-level quantum Haar wavelet transform is executed to obtain the final encrypted quantum image.The simulation experiments demonstrate that the proposed encryption algorithm has low complexity which implements information hiding to a large extent and effectively protects the information of the original image,so the effect of the encryption algorithms is good.