wavelet filter modifies the original image?

Question

nikil sharma 2015-3-3

0
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https://ww2.mathworks.cn/matlabcentral/answers/181200-wavelet-filter-modifies-the-original-image

关闭： MATLAB Answer Bot 2021-8-20

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function denoisedCoefficients = computelocalvariance(subbandCoeff,noiseVariance)

windowSize = [3 5 7 9];

[nRows nCols] = size(subbandCoeff);

denoisedCoefficients = zeros(nRows,nCols);

localVarWind3 = 0;

localVarWind5 = 0;

localVarWind7 = 0;

localVarWind9 = 0;

minLocalVariance = 0;

sumVariance = 0; try iRowOutput = 5; jRowOutput = 5;

noiseVarianceSquare = noiseVariance^2;

for iRow = 1 : nRows for jCol = 1: nCols

        %limited by the size of the largest windows i.e., 9 x 9 window
        if (iRow+windowSize(4)<nRows)  && (jCol+windowSize(4)<nCols)
            %Calculating local variance with first windowSize = 3
            for iWindowRow = iRow:(iRow+windowSize(1)-1) %windowsize is 3 x 3 
                for iWindowCol = jCol:(jCol+windowSize(1)-1)
                    sumVariance = sumVariance + ((subbandCoeff(iRow,jCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
              localVarWind3 = 1/(windowSize(1)^2) * sumVariance;
              localVarWind3 = max(0,localVarWind3);
            %Calculating local variance with second windowSize = 5
            for iWindowRow = iRow:(iRow+windowSize(2)-1)
                for iWindowCol = jCol:(jCol+windowSize(2)-1)
                    sumVariance = sumVariance + ((subbandCoeff(iRow,jCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind5 = 1/(windowSize(2)^2) * sumVariance;
            localVarWind5 = max(0,localVarWind5);
            %Calculating local variance with third windowSize = 7
            for iWindowRow = iRow:(iRow+windowSize(3)-1)
                for iWindowCol = jCol:(jCol+windowSize(3-1))
                    sumVariance = sumVariance + ((subbandCoeff(iRow,jCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind7 = 1/(windowSize(3)^2) * sumVariance;
            localVarWind7 = max(0,localVarWind7);
            %Calculating local variance with fourth windowSize = 9
            for iWindowRow = iRow:(iRow+windowSize(4)-1)
                for iWindowCol = jCol:(jCol+windowSize(4)-1)
                    sumVariance = sumVariance + ((subbandCoeff(iRow,jCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind9 = 1/(windowSize(4)^2) * sumVariance;
            localVarWind9 = max(0,localVarWind9);
            minLocalVariance = min([localVarWind3 localVarWind5 localVarWind7 localVarWind9]);
            denoisedCoefficients(iRow+4,jCol+4) = subbandCoeff(iRow,jCol)*((minLocalVariance^2)/((minLocalVariance^2)+noiseVarianceSquare));
        else 
            MatIndexExceeds = 1;
        end %if (iRow+WindowSize(4)<nRows)  && (jCol+WindowSize(4)<nCols)
    end %for jCol
end %for iRow

% 7x7 iRow = 1; for jCol = 4:nCols

        if (jCol+windowSize(3)<nCols)
            %Calculating local variance with first windowSize = 3
             for iWindowRow = iRow+2:(iRow+2+windowSize(1)-1) %windowsize is 3 x 3 
                for iWindowCol = jCol-1:(jCol-1+windowSize(1)-1)
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
              localVarWind3 = 1/(windowSize(1)^2) * sumVariance;
              localVarWind3 = max(0,localVarWind3);
            %Calculating local variance with second windowSize = 5
            for iWindowRow = iRow+1:(iRow+1+windowSize(2)-1)
                for iWindowCol = jCol-2:(jCol-2+windowSize(2)-1)
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind5 = 1/(windowSize(2)^2) * sumVariance;
            localVarWind5 = max(0,localVarWind5);
            %Calculating local variance with third windowSize = 7
            for iWindowRow = iRow:(iRow+windowSize(3)-1)
                for iWindowCol = jCol-3:(jCol-3+windowSize(3-1))
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind7 = 1/(windowSize(3)^2) * sumVariance;
            localVarWind7 = max(0,localVarWind7);
            minLocalVariance = min([localVarWind3 localVarWind5 localVarWind7]);
            denoisedCoefficients(4,jCol) = subbandCoeff(iRow,jCol)*((minLocalVariance^2)/((minLocalVariance^2)+noiseVarianceSquare));
        end %if

end w

%Moving the windows from top to bottom jCol = 1; for iRow = 4:nRows

       if (iRow+windowSize(3)<nRows)
       %Calculating local variance with first windowSize = 3
            for iWindowRow = iRow-1:(iRow-1+windowSize(1)-1) %windowsize is 3 x 3 
                for iWindowCol = jCol+2:(jCol+2+windowSize(1)-1)
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
              localVarWind3 = 1/(windowSize(1)^2) * sumVariance;
              localVarWind3 = max(0,localVarWind3);
            %Calculating local variance with second windowSize = 5
            for iWindowRow = iRow-2:(iRow-2+windowSize(2)-1)
                for iWindowCol = jCol+1:(jCol+1+windowSize(2)-1)
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind5 = 1/(windowSize(2)^2) * sumVariance;
            localVarWind5 = max(0,localVarWind5);
            %Calculating local variance with third windowSize = 7
            for iWindowRow = iRow-3:(iRow-3+windowSize(3)-1)
                for iWindowCol = jCol:(jCol+windowSize(3)-1)
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind7 = 1/(windowSize(3)^2) * sumVariance;
            localVarWind7 = max(0,localVarWind7);
       end %if row boundary limiting   
       minLocalVariance = min([localVarWind3 localVarWind5 localVarWind7]);
       denoisedCoefficients(iRow,4) = subbandCoeff(iRow,jCol)*((minLocalVariance^2)/((minLocalVariance^2)+noiseVarianceSquare));
end %for iRow, to move the windows through 4th column, from top to bottom

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 5 x 5 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

iRow = 1; for jCol = 3:nCols

        %Limiting by the size of the largest windows i.e., 5 x5 window
        if (jCol+windowSize(2)<nCols)
            %Calculating local variance with first windowSize = 3
             for iWindowRow = iRow+1:(iRow+1+windowSize(1)-1) %windowsize is 3 x 3 
                for iWindowCol = jCol-1:(jCol-1+windowSize(1)-1)
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind3 = 1/(windowSize(1)^2) * sumVariance;
            localVarWind3 = max(0,localVarWind3);
            %Calculating local variance with second windowSize = 5
            for iWindowRow = iRow:(iRow+windowSize(2)-1)
                for iWindowCol = jCol-2:(jCol-2+windowSize(2)-1)
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind5 = 1/(windowSize(2)^2) * sumVariance;
            localVarWind5 = max(0,localVarWind5);
            minLocalVariance = min([localVarWind3 localVarWind5]);
            denoisedCoefficients(3,jCol) = subbandCoeff(iRow,jCol)*((minLocalVariance^2)/((minLocalVariance^2)+noiseVarianceSquare));
        end %if

end %for jCol, to move the windows through 3rd row

jCol = 1; for iRow = 3:(nRows-windowSize(2)+1)

        if (jCol+windowSize(2)<nCols)
            %Calculating local variance with first windowSize = 3
             for iWindowRow = iRow-1:(iRow-1+windowSize(1)-1) %windowsize is 3 x 3 
                for iWindowCol = jCol+1:(jCol+1+windowSize(1)-1)
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind3 = 1/(windowSize(1)^2) * sumVariance;
            localVarWind3 = max(0,localVarWind3);
            %Calculating local variance with second windowSize = 5
            for iWindowRow = iRow-2:(iRow-2+windowSize(2)-1)
                for iWindowCol = jCol:(jCol+windowSize(2)-1)
                     if (iWindowRow>45)
                        err =1;
                    end
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind5 = 1/(windowSize(2)^2) * sumVariance;
            localVarWind5 = max(0,localVarWind5);
            minLocalVariance = min([localVarWind3 localVarWind5]);
            denoisedCoefficients(iRow,3) = subbandCoeff(iRow,jCol)*((minLocalVariance^2)/((minLocalVariance^2)+noiseVarianceSquare));
        end %if

end %for jCol, to move the windows through 3rd col

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%3 x 3%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %Performing the operations for 3 x 3 window

iRow = 1; for jCol = 2:nCols

        if (jCol+windowSize(1)<nCols)
            %Calculating local variance with first windowSize = 3
             for iWindowRow = iRow:(iRow+windowSize(1)-1) %windowsize is 3 x 3 
                for iWindowCol = jCol-1:(jCol-1+windowSize(1)-1)
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind3 = 1/(windowSize(1)^2) * sumVariance;
            localVarWind3 = max(0,localVarWind3);
            minLocalVariance = localVarWind3;
            denoisedCoefficients(2,jCol) = subbandCoeff(iRow,jCol)*((minLocalVariance^2)/((minLocalVariance^2)+noiseVarianceSquare));
        end %if

end %for jCol, to move the windows through 3rd row

%Performing the operations for 3 x 3 window %Moving the windows from top to bottom jCol = 1; for iRow =2:nRows-windowSize(1)+1

        %Limiting by the size of the largest windows i.e., 3 x3 window
        if (jCol+windowSize(2)<nCols)
            %Calculating local variance with first windowSize = 3
             for iWindowRow = iRow-1:(iRow-1+windowSize(1)-1) %windowsize is 3 x 3 
                for iWindowCol = jCol:(jCol+windowSize(1)-1)
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind3 = 1/(windowSize(1)^2) * sumVariance;
            localVarWind3 = max(0,localVarWind3);
            minLocalVariance = localVarWind3;
            denoisedCoefficients(iRow,2) = subbandCoeff(iRow,jCol)*((minLocalVariance^2)/((minLocalVariance^2)+noiseVarianceSquare));
        end %if

end %******************7 x 7 ********************************************** %Moving the windows from left to right near the bottom boundary iRow =nRows-7+1; %To fit the 7 x 7 window for jCol = 1:nCols

        if (jCol+windowSize(3)<nCols) 
            %Calculating local variance with first windowSize = 3
             for iWindowRow = iRow:(iRow+windowSize(1)-1) %windowsize is 3 x 3 
                for iWindowCol = jCol:(jCol+windowSize(1)-1)
                    if (iWindowRow>45)
                        err =1;
                    else if (iWindowCol>45)
                            err = 2;
                        end
                    end
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
              localVarWind3 = 1/(windowSize(1)^2) * sumVariance;
              localVarWind3 = max(0,localVarWind3);
            %Calculating local variance with second windowSize = 5
            for iWindowRow = iRow+1:(iRow+1+windowSize(2)-1)
                for iWindowCol = jCol+1:(jCol-2+windowSize(2)-1)
                    if (iWindowRow>45)
                        err =1;
                    else if (iWindowCol>45)
                            err = 2;
                        end
                    end
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind5 = 1/(windowSize(2)^2) * sumVariance;
            localVarWind5 = max(0,localVarWind5);
            %Calculating local variance with third windowSize = 7
            for iWindowRow = iRow:(iRow+windowSize(3)-1)
                for iWindowCol = jCol:(jCol-3+windowSize(3-1))
                    if (iWindowRow>45)
                        err =1;
                    else if (iWindowCol>45)
                            err = 2;
                        end
                    end
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind7 = 1/(windowSize(3)^2) * sumVariance;
            localVarWind7 = max(0,localVarWind7);
            minLocalVariance = min([localVarWind3 localVarWind5 localVarWind7]);
            denoisedCoefficients(4,jCol) = subbandCoeff(iRow,jCol)*((minLocalVariance^2)/((minLocalVariance^2)+noiseVarianceSquare));
        end %if

end %for jCol, to move the windows through 4th row

%Moving the windows from top to bottom jCol = 1; for iRow = 4:nRows

       if (iRow+windowSize(3)<nRows)
       %Calculating local variance with first windowSize = 3
            for iWindowRow = iRow-1:(iRow-1+windowSize(1)-1) %windowsize is 3 x 3 
                for iWindowCol = jCol+2:(jCol+2+windowSize(1)-1)
                     if (iWindowRow>45)
                        err =1;
                    else if (iWindowCol>45)
                            err = 2;
                        end
                    end
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
              localVarWind3 = 1/(windowSize(1)^2) * sumVariance;
              localVarWind3 = max(0,localVarWind3);
            %Calculating local variance with second windowSize = 5
            for iWindowRow = iRow-2:(iRow-2+windowSize(2)-1)
                for iWindowCol = jCol+1:(jCol+1+windowSize(2)-1)
                     if (iWindowRow>45)
                        err =1;
                    else if (iWindowCol>45)
                            err = 2;
                        end
                    end
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind5 = 1/(windowSize(2)^2) * sumVariance;
            localVarWind5 = max(0,localVarWind5);
            %Calculating local variance with third windowSize = 7
            for iWindowRow = iRow-3:(iRow-3+windowSize(3)-1)
                for iWindowCol = jCol:(jCol+windowSize(3-1))
                     if (iWindowRow>45)
                        err =1;
                    else if (iWindowCol>45)
                            err = 2;
                        end
                    end
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind7 = 1/(windowSize(3)^2) * sumVariance;
            localVarWind7 = max(0,localVarWind7);
       end %if row boundary limiting   
       minLocalVariance = min([localVarWind3 localVarWind5 localVarWind7]);
       denoisedCoefficients(iRow,nCols-3) = subbandCoeff(iRow,jCol)*((minLocalVariance^2)/((minLocalVariance^2)+noiseVarianceSquare));%nCol-3 is the central pixel for 7x7 window
end %for iRow, to move the windows through 4th column, from top to bottom

%******************5 x 5 **********************************************

%Moving the windows from left to right near the bottom boundary iRow =nRows-5+1; for jCol = 1:nCols

        if (jCol+windowSize(2)<nCols) 
            %Calculating local variance with first windowSize = 3
             for iWindowRow = iRow:(iRow+windowSize(1)-1) %windowsize is 3 x 3 
                for iWindowCol = jCol:(jCol+windowSize(1)-1)
                     if (iWindowRow>45)
                        err =1;
                    else if (iWindowCol>45)
                            err = 2;
                        end
                    end
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
              localVarWind3 = 1/(windowSize(1)^2) * sumVariance;
              localVarWind3 = max(0,localVarWind3);
            %Calculating local variance with second windowSize = 5
            for iWindowRow = iRow+1:(iRow+windowSize(2)-1)
                for iWindowCol = jCol+1:(jCol-2+windowSize(2)-1)
                     if (iWindowRow>45)
                        err =1;
                    else if (iWindowCol>45)
                            err = 2;
                        end
                    end
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind5 = 1/(windowSize(2)^2) * sumVariance;
            localVarWind5 = max(0,localVarWind5);
            minLocalVariance = min([localVarWind3 localVarWind5]);
            denoisedCoefficients(iRow,jCol) = subbandCoeff(iRow,jCol)*((minLocalVariance^2)/((minLocalVariance^2)+noiseVarianceSquare));
        end %if

end %for jCol, to move the windows through 4th row

%Moving the windows from top to bottom jCol = 1; for iRow = 3:nRows

       if (iRow+windowSize(3)<nRows)
       %Calculating local variance with first windowSize = 3
            for iWindowRow = iRow-1:(iRow-1+windowSize(1)-1) %windowsize is 3 x 3 
                for iWindowCol = jCol+2:(jCol+2+windowSize(1)-1)
                     if (iWindowRow>45)
                        err =1;
                    else if (iWindowCol>45)
                            err = 2;
                        end
                    end
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
              localVarWind3 = 1/(windowSize(1)^2) * sumVariance;
              localVarWind3 = max(0,localVarWind3);
            %Calculating local variance with second windowSize = 5
            for iWindowRow = iRow-2:(iRow-2+windowSize(2)-1)
                for iWindowCol = jCol+1:(jCol+1+windowSize(2)-1)
                    if (iWindowRow>45)
                        err =1;
                    else if (iWindowCol>45)
                            err = 2;
                        end
                    end
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
            localVarWind5 = 1/(windowSize(2)^2) * sumVariance;
            localVarWind5 = max(0,localVarWind5);
       end %if row boundary limiting   
       minLocalVariance = min([localVarWind3 localVarWind5]);
       denoisedCoefficients(iRow,nCols-3) = subbandCoeff(iRow,jCol)*((minLocalVariance^2)/((minLocalVariance^2)+noiseVarianceSquare));%nCol-3 is the central pixel for 7x7 window
end %for iRow, to move the windows through 4th column, from top to bottom

%******************3 x 3 ********************************************** %Moving the windows from left to right near the bottom boundary iRow =nRows-3+1; %To fit the 3 x 3 window for jCol = 1:nCols

        if (jCol+windowSize(2)<nCols) 
            %Calculating local variance with first windowSize = 3
             for iWindowRow = iRow:(iRow+windowSize(1)-1) %windowsize is 3 x 3 
                for iWindowCol = jCol:(jCol+windowSize(1)-1)
                     if (iWindowRow>45)
                        err =1;
                    else if (iWindowCol>45)
                            err = 2;
                        end
                    end
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
              localVarWind3 = 1/(windowSize(1)^2) * sumVariance;
              localVarWind3 = max(0,localVarWind3);
            minLocalVariance = localVarWind3;
            denoisedCoefficients(iRow,jCol) = subbandCoeff(iRow,jCol)*((minLocalVariance^2)/((minLocalVariance^2)+noiseVarianceSquare));
        end %if

end %for jCol, to move the windows through 4th row

%Moving the windows from top to bottom jCol = 1; for iRow = 3:nRows

       if (iRow+windowSize(3)<nRows)
       %Calculating local variance with first windowSize = 3
            for iWindowRow = iRow-1:(iRow-1+windowSize(1)-1) %windowsize is 3 x 3 
                for iWindowCol = jCol+2:(jCol+2+windowSize(1)-1)
                     if (iWindowRow>45)
                        err =1;
                    else if (iWindowCol>45)
                            err = 2;
                        end
                    end
                    sumVariance = sumVariance + ((subbandCoeff(iWindowRow,iWindowCol)^2) - noiseVarianceSquare);
                end %iWindowCol
            end %iWindowRow
              localVarWind3 = 1/(windowSize(1)^2) * sumVariance;
              localVarWind3 = max(0,localVarWind3);
       end %if row boundary limiting   
       minLocalVariance = localVarWind3;
       denoisedCoefficients(iRow,nCols-3) = subbandCoeff(iRow,jCol)*((minLocalVariance^2)/((minLocalVariance^2)+noiseVarianceSquare));%nCol-3 is the central pixel for 7x7 window
end %for iRow, to move the windows through 4th column, from top to bottom

for iRow = 1: nRows denoisedCoefficients(iRow,1) = denoisedCoefficients(iRow, 2); %copying values from 2nd column to first column denoisedCoefficients(iRow,nCols) = denoisedCoefficients(iRow, nCols-1);%copying values from n-1th column to nth column end for jCol = 1: nCols denoisedCoefficients(1,jCol) = denoisedCoefficients(2, jCol);%Copying values from 2nd row to first row. denoisedCoefficients(nRows,jCol) = denoisedCoefficients(nRows-1,jCol);%Copying values from n-1th row to nth row. end catch ex exception=1; end

    Hi I am Trying to get denoised image..Step are as below---
EXTRACTPRNU(I )
Apply a wavelet decomposition in 4 levels to I 
foreach wavelet decomposition level do 4 foreach component c ∈ {H, V, D} do
Compute the local variance; 
Compute noiseless wavelet components applying the Wiener filter to the variance; 7 Obtain I clean by applying the inverse wavelet transform with clean components calculated;
But Denoised image is altered