implementation for iterative wiener filter

10 vues (au cours des 30 derniers jours)
gehad attia
gehad attia le 1 Août 2012
This is my implementation in the iterative wiener filter in this paper : http://www.tsc.uc3m.es/~navia/LATDS07/IterativeWienerFilter.pdf
I wish it will help anyone
function wiener()
clc;
clear;
f=im2double(rgb2gray(imread('lena.jpg')));
imshow(f);
f=imresize(f,[32 32]);
figure,imshow(f)
[r c]=size(f);
h=fspecial('average');
g=imfilter(f,h,'circular');
s_avg = sum(sum(f))/(r*c);
SNR=90;
n_sigma=s_avg/(10^(SNR/20));
n=n_sigma*randn(size(f));
g=g+n;
[Nf,Mf]=size(g);
[Nh,Mh]=size(h);
L1=floor(Nh/2);
L2=floor(Mh/2);
H=zeros(Nf*Mf);
k=1;
for row=1:Mf,
for col=1:Nf,
hh=zeros(Nf,Mf);
hh(1:Nh,1:Mh)=h;
hh=circshift(hh,[col-1-L1,row-1-L2]);
H(k,:)=hh(:)';
k=k+1;
end
end
%%make vector of m^2*1 of the f,n,g
f=reshape(f',size(f,1)*size(f,2),1);
g=reshape(g',size(g,1)*size(g,2),1);
n=reshape(n',size(n,1)*size(n,2),1);
%%%calculate the autocorrelation matrix of f ,g,n
u=mean(g);
g1=autom(g-u);
Rg=toeplitz(g1);
n1=autom(n);
Rn=toeplitz(n1);%%%%%
Rf=Rg;
steps=10;
mse=zeros(1,steps);
for i=1:steps
B=Rf*H'*inv( (H*Rf*H') +Rn);
fHat=B*(g);
Rf=B*Rg*B';
im=reshape(fHat,[32 32]);
g=reshape(g,[32 32]);
%figure,imshow(im',[]);
mse(1,i) = sum(sum((im(:)-g(:))));
g=reshape(g',size(g,1)*size(g,2),1);
end
t=1:steps;
mse
plot(t,mse);
end
function [Rxx]=autom(x)
N=length(x);
Rxx=zeros(1,N);
for m=1: N+1
for n=1: N-m+1
Rxx(m)=(Rxx(m)+x(n)*x(n+m-1))/N-m+1;
end;
end
end
  2 commentaires
Walter Roberson
Walter Roberson le 1 Août 2012
This should probably go into the File Exchange (FEX)
Walter Roberson
Walter Roberson le 1 Août 2012
Please read the guide to tags and retag this; see http://www.mathworks.co.uk/matlabcentral/answers/43073-a-guide-to-tags

Connectez-vous pour commenter.

Réponses (0)

Catégories

En savoir plus sur Logical dans Help Center et File Exchange

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by