diff toolboxes/AudioInpaintingToolbox/Solvers/inpaintFrame_OMP.m @ 138:56d719a5fd31 ivand_dev

Audio Inpaintin Toolbox

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolboxes/AudioInpaintingToolbox/Solvers/inpaintFrame_OMP.m	Thu Jul 21 14:27:47 2011 +0100
@@ -0,0 +1,77 @@
+function y = inpaintFrame_OMP(problemData,param)
+% Inpainting method based on OMP 
+%
+% Usage: y = inpaintFrame_OMP(problemData,param)
+%
+%
+% Inputs:
+%          - problemData.x: observed signal to be inpainted
+%          - problemData.Imiss: Indices of clean samples
+%          - param.D - the dictionary matrix (optional if param.D_fun is set)
+%          - param.D_fun - a function handle that generates the dictionary 
+%          matrix param.D if param.D is not given. See, e.g., DCT_Dictionary.m and Gabor_Dictionary.m
+%          - param.wa - Analysis window
+%
+% Outputs:
+%          - y: estimated frame
+%
+%
+% -------------------
+%
+% Audio Inpainting toolbox
+% Date: June 28, 2011
+% By Valentin Emiya, Amir Adler, Michael Elad, Maria Jafari
+% This code is distributed under the terms of the GNU Public License version 3 (http://www.gnu.org/licenses/gpl.txt).
+% ========================================================
+% To do next: use a faster implementation of OMP
+
+%% Load data and parameters
+
+x = problemData.x;
+IObs = find(~problemData.IMiss);
+p.N = length(x);
+   E2 = param.OMPerr^2;
+   E2M=E2*length(IObs);
+
+   wa = param.wa(param.N);
+
+
+%% Build and normalized dictionary
+% build the dictionary matrix if only the dictionary generation function is given
+if ~isfield(param,'D')
+   param.D = param.D_fun(param);
+end
+Dict=param.D(IObs,:);
+W=1./sqrt(diag(Dict'*Dict));
+Dict=Dict*diag(W);
+xObs=x(IObs);
+
+%% OMP iterations
+residual=xObs;
+maxNumCoef = param.sparsityDegree;
+indx = [];
+currResNorm2 = E2M*2; % set a value above the threshold in order to have/force at least one loop executed
+j = 0;
+while currResNorm2>E2M && j < maxNumCoef,
+   j = j+1;
+   proj=Dict'*residual;
+   [dum pos] = max(abs(proj));
+   indx(j)=pos;
+   
+   a=pinv(Dict(:,indx(1:j)))*xObs;
+   
+   residual=xObs-Dict(:,indx(1:j))*a;
+   currResNorm2=sum(residual.^2);
+end
+
+%% Frame Reconstruction
+indx(length(a)+1:end) = [];
+
+Coeff = sparse(size(param.D,2),1);
+if (~isempty(indx))
+   Coeff(indx) = a;
+   Coeff = W.*Coeff;
+end
+y = param.D*Coeff;
+
+return