采用低通性质的平滑函数为高斯函数，根据他的一阶导数、二阶导数作为小波基函数进行突变点分析。 -The use of low-pass nature of the smoothing function for the Gaussian function, according to his first derivative, second derivative wavelet basis function as a point mutation analysis.

Leung-Malik (LM)滤波器组由48个滤波器组成-The LM set is a multi scale, multi orientation filter bank with 48 filters. It consists of first and second derivatives of Gaussians at 6 orientations and 3 scales making a total of 36 8 Laplacian of Gaussian (LOG) filt

Segmentation of retinal blood vessels by using a matched filter based on second derivative of Gaussian