Research And Application Of Quantum Gray-scale Image

Quantum information is the highly technical combination of quantum mechanics andmodern information technology having far-reaching research significance. As an importantbranch of quantum information, quantum computing which possesses characteristics ofgreat-efficiency and high-speed will lead the transition from classical computer to quantumcomputer at last. Quantum image processing is an emerging interdisciplinary field integratedquantum information and classical image processing, which aims at making full use of thesuperiorities of quantum information into each stage of image processing.Learning and analyzing the basic knowledge of quantum information, the thesissynthesizes the properties of parallelism, superposition and entanglement of quantum statewith the procedures of representation, transformation, encryption and decryption of imageprocessing to finish the series operations of "expression proposition–transformationdesign-application" on quantum gray-scale image. The main researches are described asfollows:(1) Propose the quantum gray-scale image expression and the storage representationSimilar to the classical image processing, in quantum counterpart, the contents stored inquantum states are the color information and position information of image. The researchobject in this thesis mainly focuses on quantum gray-scale image, for which the storage inquantum states are information of gray-scale and position. By making full advantage of theinfinite gray-scale range for gray scale image, in the text, an expression for quantumgray-scale image is proposed and demonstrated. Based on the expression, the state storingpattern of quantum image pointer is emerged through the integration of the pixel mappingwhich is one of the characteristic of the expression and pointer-storing which is an efficientstoring mode in classical computer. In addition, the storage of quantum image pointer isfurther applied to the quantum image transformation.(2) Design quantum circuits and the Matlab realization for quantum gray-scale imagegeometric transformationsThe geometric transforms for quantum image processing are also existed correspondingto the geometric transformations in classical image processing. Based on the work in prior, thenext part makes the realization of geometric transforms, such as translation,addition-subtraction, mirror-image and sub-block exchange by means of quantum circuits andMatlab program designs respectively. The quantum circuits are obtained in terms of theapplications of elementary quantum gates in quantum computation. While the realization ofMatlab programs for quantum computation have to switch it to matrix manipulation firstly with the matrixing of quantum states, and then the quantum states are transformed into thedesign of Matlab programs.(3) Propose encryption and decryption algorithms for quantum gray-scale image based theprior expression and geometric transformsCryptography is the essential subject to protect important data and network security.Although following the symmetric cryptosystem for which the participations in thecommunication keep exactly the same keys, the special for the encryption and decryptionalgorithms proposed in this paper lays in the operational objectives, the quantum image.Through the combination of the proposals in previous, the encryption and decryptionalgorithms on quantum gray-scale images is accomplished in theory and experiencesimulation, which could ensure the confidentiality and security of the information in delivery.The algorithms belong to the application of quantum image geometric transformations, forfurther, the new explorations for quantum image cryptography researches.