%This program implements fringe pattern demodulation using the continuous 
%wavelet transform algorithm and employs the phase estimation method and
%maximum ridge extraction algorithms. The Shannon mother wavelet is used
%This program is written By Munther Gdeisat at The General Engineering
%Research Institute at Liverpool John Moores University (UK) on 8th
%Febraury 2009.
clear; close all; clc;
S=256;
x=-S+1:1:S;
[X, Y] = meshgrid(x,x);
aa = size(X);
noise = randn(aa(1), aa(2));
shape=peaks(2*S);
figure(1)
mesh(shape)
fo = 1./16;
Beta=1;
fringes = cos(2.*pi.*fo.*X + Beta*shape) + 0*noise;
figure(2)
colormap(gray(256))
imagesc(fringes)
xlabel('Pixels'); ylabel('Pixels')
for k=1:2*S
    y = fringes(k,:);
    c=cwt(y,1:1:64, 'shan1-1.5');
    A=abs(c);
    psi=angle(c);
    [maximum,row_index]=max(A);
    for m=1:2*S
        wrappedPhase(k,m)=psi(row_index(1,m),m);
    end
end
%Itoh Phase unwrapper
unwrappedPhase = unwrap(unwrap(wrappedPhase)')';
unwrappedPhase = -(unwrappedPhase + 2*pi*fo.*X);
error=unwrappedPhase-shape;
error=error-mean(mean(error));
figure(3); colormap(gray(256));imagesc(wrappedPhase)
figure(4);mesh(unwrappedPhase);xlabel('Pixels'); ylabel('Pixels'); zlabel('Phase (rad)')
figure(5);mesh(error);xlabel('Pixels'); ylabel('Pixels'); zlabel('error (rad)')