lambada=633e-7;
k=2*pi/lambada;
changdu=5;kuandu=5;
z1=10;
M=64;N=64;
dx=（M-1）/changdu;dy=（N-1）/kuandu;??????????????????????????????????????????%頻域間隔
fx=（31:-1:-32）‘*ones（1M）*dx/63;????????????????????????????????????????%頻域坐標
fy=ones（N1）*（31:-1:-32）*dy/63;
a=imread（‘kj.bmp‘）;
subplo