specxture1.m

图像经过二维傅立叶频谱分析后

function [srad,sang,SS]=specxture1(f)
SS=fftshift(fft2(f));
SS=abs(SS);
SS=SS.*conj(SS); 
[M,N]=size(SS);
x0=M/2+1;
y0=N/2+1;
rmax=min(M,N)/2-1;
srad=zeros(1,rmax);
srad(1)=SS(x0,y0);
for r=2:rmax
    [xc,yc]=halfcircle(r,x0,y0);
    srad(r)=sum(SS(sub2ind(size(SS),xc,yc)));
end
[xc,yc]=halfcircle(rmax,x0,y0);
sang=zeros(1,length(xc));
for a=1:length(xc)
    [xr,yr]=radial(x0,y0,xc(a),yc(a));
    sang(a)=sum(SS(sub2ind(size(SS),xr,yr)));
end
SS=mat2gray(log(1+SS));