常用图象滤波器的设计方法，实现一个通用的高通、低通滤波器函数，其中又分别实现理想、巴特沃思和高斯滤波形式，用实现的函数对图象进行高通处理，将所给图象增加噪声后再进行低通处理，处理后分别进行伪彩色增强-Top image filter design method, to achieve a common high-pass, low-pass filter function, which achieve the ideal, Butterworth and the form of Gaussian