function plot_img(x,y,img,scope)
%x,y:指定x,y坐標
%img:二維復數(shù)矩陣
%scope:顯示動態(tài)范圍0~120dB
%NUDT,Hezhihua
%E-mail:skynismile@yahoo.com.cn
%last update:23/6/2005

G=20*log10(abs(img)+1e-6);
gm=max(max(G));
gn=gm-scope;%顯示動態(tài)范圍
G=255/(gm-gn)*(G-gn).*(G>gn);
imagesc(x,y,-G);
colormap(gray);
axis xy;