restaura_block

PURPOSE ^

function [sol]=restaura_block(observado,B,F,lambdas,criterio_lambda)

SYNOPSIS ^

function [sol,valorlambda]=restaura_block(observado,B,F,M,N,lambdas,criterio_lambda)

DESCRIPTION ^

 function [sol]=restaura_block(observado,B,F,lambdas,criterio_lambda)

   observado:   block
   B:           blurring operator in Fourier
   F:           regularization operator in Fourier
   lambdas:     vector with the lambda values
   criterio_lambda:  selectiong lambda method

   It gives back
   sol:         Restored block

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

0001 % function [sol]=restaura_block(observado,B,F,lambdas,criterio_lambda)
0002 %
0003 %   observado:   block
0004 %   B:           blurring operator in Fourier
0005 %   F:           regularization operator in Fourier
0006 %   lambdas:     vector with the lambda values
0007 %   criterio_lambda:  selectiong lambda method
0008 %
0009 %   It gives back
0010 %   sol:         Restored block
0011 
0012 function [sol,valorlambda]=restaura_block(observado,B,F,M,N,lambdas,criterio_lambda)
0013 
0014 M = size(observado,1);
0015 
0016 nlamb=length(lambdas);
0017 
0018 rand('seed',1)
0019 vectorsol = rand(nlamb*M,M);
0020 
0021 [dummy,varianzaruido] = wiener2(observado,[2 2]);
0022 
0023 energB = sum(sum(abs(B).^2));
0024 
0025 Bconj = conj(B);
0026 
0027 BB = B.*Bconj;
0028 
0029 operador = format_operator(F);
0030 
0031 F = operador;
0032 
0033 energF = sum(sum(abs(F).^2));
0034 
0035 if (energF==0)
0036    F = sqrt(energB)*F;
0037 else
0038    F = sqrt(energB)*F/sqrt(energF);
0039 end
0040 
0041 FF = F.*conj(F);
0042 
0043 ang = linspace(0,pi/2,5);
0044 v = [reverse(cos(ang)) ones(1,M-2*5) cos(ang)];
0045 pesos = v'*v;
0046 
0047 observado = observado.*pesos + (1-pesos).*mean(mean(observado));
0048 
0049 cub=fft2(observado);
0050 
0051 espdeg = cub;
0052 
0053 x=zeros(nlamb,1);
0054 y=zeros(nlamb,1);
0055 
0056 for k=1:nlamb
0057 
0058    lambda=lambdas(k);
0059 
0060    Hinv=Bconj./( BB + lambda^2*FF);
0061 
0062    fftsol = Hinv.*cub;
0063 
0064    rF = B.*fftsol - cub;
0065 
0066    x(k) = norm(rF(:))/M;
0067 
0068    pF = F.*fftsol;
0069 
0070    y(k)=norm(pF(:))/M;
0071 
0072 end
0073 
0074 if (nlamb==1)
0075    valorlambda=lambda;
0076 else
0077    valorlambda = seleccion_lambda(x,y,lambdas,varianzaruido,criterio_lambda);
0078 end
0079 
0080 if (length(valorlambda)>1)
0081    valorlambda = 2;
0082 end
0083 
0084 distancias = abs(lambdas-valorlambda);
0085 pos = find(distancias==min(distancias));
0086 pos = pos(1);
0087 
0088 Hinv=Bconj./( BB + valorlambda^2*FF);
0089 
0090 sol=real(ifft2(Hinv.*cub));
0091

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