Retinal Vascular Image Edge Detection Based On Fractional Differential

As a mathematical problem, fractional calculus has a long history. Its essence is to extend the calculus order of fractional calculus from the integer to the fraction(plural).In recent years, the rapid development of digital computing technologies provides objective conditions for the concept of fractional calculus, transforming from theoretical research to engineering practice. Now, fractional calculus has been widely used in many fields of engineering practice, and because of its unique advantages, more and more researchers start to pay attention to this concept.The edge is the richest information region of the digital image, it directly expresses the basic information of the digital image. The edge detection of retinal vascular image can predict the occurrence of the disease and improve the diagnostic accuracy, and play an important role in the field of authentication and security. According to the basic theory of fractional calculus, on the basis of previous studies, combined with vector synthesis theorem, this paper proposes an improved medical image edge detection method based on fractional differential. Experimental results show that:the algorithm not only effectively extracts the contour edge of the retinal vessels image, but also nonlinear retain the area of texture details information-rich in the image.The overall effect is significantly better than the traditional detection algorithm. In this paper, the major works are made as follow:(1)This paper presents and analyzes the basic theory of fractional calculus, and compares fractional calculus and integer-order calculus;(2)This paper briefly introduces the basic principles of digital image edge detection and some edge detection methods, and analyzes several traditional edge detection operators;(3)By analyzing the characteristics of fractional differential acting on the signal, this paper suggests fractional differential is more suitable for dealing with the retinal image compared to integer-order differential theoretically. On the basis of previous studies, this paper improves the medical image edge detection method based on fractional differential combined the vector synthesis theorem;(4)Matlab simulation experiments prove the fact that the edge detection algorithm based on fractional differential can better extract retinal image edge information compared to traditional algorithm.The main innovations of this paper are as followed:(1)Constructs an approximate sixteen directions fractional differential template according to vector synthesis theorem and difference function deduced by fractional calculus G-L definition;(2)The paper proposes a medical image edge detection method based on the improved fractional differential,and show that the method can preserve more detail information in the medical image,and provide a more reliable protection for medical diagnosis.