First , agriculture noise image " ano " was processed by wavelet transform to have a low frequency image " a1 " and three high frequency images " hd1 ", " vd1 " and " dd1 " from horizontal , vertical and diagonal directions ;
该方法首先对含噪农产品图像ano做第一次小波变换得到低频图像a1和水平、垂直和对角三方向的高频图像hd1、vd1及dd1；
dd1