clear;close all;clc;
Spinput=double(imread('lenna.bmp'));
Froutput=double(imread('E.bmp'));

%phase=phaseSL(Master,Watermark);
%function [phase]=PhaseSL(Spinput,Froutput)

input=Spinput;
[m,n]=size(input);
a=Froutput;
E2=sqrt(a);
b=Spinput;
E1=sqrt(b);
iter=1;         % 迭代次數
iterations=100;
E_1=rand(m);
while(iter<iterations+1)
    E_plane_2=fftshift(fft2(E1));
    E_2=E_plane_2;
    I_2=E_2.*conj(E_2);
    E_plane_2_new=E2.*exp(i.*angle(E_plane_2));
    E_plane_1=fftshift(ifft2(E_plane_2_new));
    phase=angle(E_plane_1);
    E_1=E1.*exp(i.*angle(E_plane_1));
    iter=iter+1;
end
figure;imshow(phase,[]);title('相位圖');
imwrite(mat2gray(phase),'phase_test100.bmp');
Read_phase=imread('phase_test100.bmp');
Re_phase=fft2(double(Read_phase));
imwrite(mat2gray(phase),'phase_test100.bmp');
figure;imshow(log(abs(Re_phase)+1),[]);title('復原');