叠加椒盐噪声后进行二阶巴特沃斯(Butterworth)低通滤波,最后显示处理结果. 直接解压后将图片和程序放在同一个文件夹里.-after second-order Butterworth (Butterworth) low-pass filtering, Final results showed. Photo will be directly extracted and procedures on the same document folder.