clc;
clear all;
close all;
N=180;
N2=N ^ 2;
I=the phantom (N);
Theta=linspace (0180181);
Theta equals theta (1:18 0);
P_num=260;
P=radon (I, theta);
The delta=1;
[W_ind, W_dat]=medfuncSystemMatrix (theta, N, P_num, delta);
F=zeros (N2, 1);
Lambda=0.25;
C=0;
Irt_num=10;
While (c For j=1: length (theta)
For I=1:1: P_num
U=W_ind ((j - 1) * P_num + I, :);
V=W_dat ((j - 1) * P_num + I, :);
If any (u)==0
continue;
End
W=zeros (1, N2);
Ind=u> 0;
W (u (ind))=v (ind);
PP=w * F;
C=(P (I, j) - PP)/sum (w. ^ 2) * w ';
F=F + lambda x C;
End
End
F (F <0)=0;
C=c + 1;
End
F=reshape (F, N, N) ';
Figure, hold on
Subplot (1, 2, 1), imshow (I), xlabel (' 256 * 256 (a) the head phantom ');
,2,2 subplot (1), imshow (F), xlabel (' (b) ART reconstructed head phantom ');