lvbofantou.m

来自「几个图象处理程序」· M 代码 · 共 31 行

%滤波反投影
I=phantom(256);
th=1:180;
g=radon(I,th);
G=zeros(367,180);
GG=zeros(367,180);
r=-1.414:1.414/183:1.414;
F=zeros(256,256);
x=-1:2/255:1;
y=1:-2/255:-1;
clf
%对每个角度进行修正，反投影
for th=1:180;
    G(:,th)=fftshift(fft(g(:,th)));
    GG(:,th)=G(:,th).*(abs(r'));
    GG_ifft(:,th)=ifft(ifftshift(GG(:,th)));
%直接反投
for m=1:256
    for n=1:256
            R=(x(m)*cos(th*pi/180)+y(n)*sin(th*pi/180));
            rr=round(R/1.414*183)+184;
            F(n,m)=F(n,m)+GG_ifft(rr,th);           
    end
end
end
imagesc(real(F))