wiener filter OpenCV - c++

Question

Basically I am trying to implement a very basic version of the Wiener filter on a grey scale image, using the a stripped down Wiener equation: (1/(SNR))*DFT(Image) after which I take the IDFT of the whole thing. My problem is that my output image which is supposed to be filtered looks exactly like the input, and therefore it seems that the pixel values aren't changing at all. Can anyone please indicate to me where I am going wrong? Here's the code I am currently using:
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv/cv.hpp"
#include "opencv/cxcore.hpp"
#include <iostream>
using namespace cv;
using namespace std;
void updateMag(Mat complex);
Mat updateResult(Mat complex);
Mat computeDFT(Mat image);
Mat DFT2(Mat I);
void shift(Mat magI);
int kernel_size = 0;
int main( int argc, char** argv )
{
Mat result;
String file;
file = " << SAMPLE FILE >>";
Mat image = imread("/Users/John/Desktop/house.png", CV_LOAD_IMAGE_GRAYSCALE);
namedWindow( "Orginal window", CV_WINDOW_AUTOSIZE );// Create a window for display.
imshow( "Orginal window", image ); // Show our image inside it.
float x = 1/0.001;
Mat complex = computeDFT(image); // DFT of image
updateMag(complex); // compute magnitude of complex, switch to logarithmic scale and display...
Mat fourierImage(complex.size(), complex.type());
fourierImage = cv::Scalar::all(x);
//cout<< "Fourier = " << endl << fourierImage << endl;
//Mat complexFourier = computeDFT(fourierImage);
//cout << "1" << endl << complexFourier.type() << endl << complexFourier.type() << endl;
//complex = complex.mul(fourierImage);
//mulSpectrums(complex, fourierImage, complex, DFT_ROWS);
complex = complex.mul(x);
result = updateResult(complex); // do inverse transform and display the result image
waitKey(0);
return 0;
}
Mat updateResult(Mat complex)
{
Mat work;
//work.convertTo(work, CV_32F);
idft(complex, work);
//dft(complex, work, DFT_INVERSE + DFT_SCALE);
Mat planes[] = {Mat::zeros(complex.size(), complex.type()), Mat::zeros(complex.size(), complex.type())};
split(work, planes); // planes[0] = Re(DFT(I)), planes[1] = Im(DFT(I))
magnitude(planes[0], planes[1], work); // === sqrt(Re(DFT(I))^2 + Im(DFT(I))^2)
normalize(work, work, 1, 0, NORM_MINMAX);
imshow("result", work);
return work;
}
void updateMag(Mat complex )
{
Mat magI;
Mat planes[] = {Mat::zeros(complex.size(), CV_32F), Mat::zeros(complex.size(), CV_32F)};
split(complex, planes); // planes[0] = Re(DFT(I)), planes[1] = Im(DFT(I))
magnitude(planes[0], planes[1], magI); // sqrt(Re(DFT(I))^2 + Im(DFT(I))^2)
// switch to logarithmic scale: log(1 + magnitude)
magI += Scalar::all(1);
log(magI, magI);
shift(magI);
normalize(magI, magI, 1, 0, NORM_INF); // Transform the matrix with float values into a
// viewable image form (float between values 0 and 1).
imshow("spectrum", magI);
}
Mat computeDFT(Mat image) {
Mat padded; //expand input image to optimal size
int m = getOptimalDFTSize( image.rows );
int n = getOptimalDFTSize( image.cols ); // on the border add zero values
copyMakeBorder(image, padded, 0, m - image.rows, 0, n - image.cols, BORDER_CONSTANT, Scalar::all(0));
Mat planes[] = {Mat_<float>(padded), Mat::zeros(padded.size(), CV_32F)};
Mat complex;
merge(planes, 2, complex); // Add to the expanded another plane with zeros
dft(complex, complex, DFT_COMPLEX_OUTPUT); // furier transform
return complex;
}
void shift(Mat magI) {
// crop if it has an odd number of rows or columns
magI = magI(Rect(0, 0, magI.cols & -2, magI.rows & -2));
int cx = magI.cols/2;
int cy = magI.rows/2;
Mat q0(magI, Rect(0, 0, cx, cy)); // Top-Left - Create a ROI per quadrant
Mat q1(magI, Rect(cx, 0, cx, cy)); // Top-Right
Mat q2(magI, Rect(0, cy, cx, cy)); // Bottom-Left
Mat q3(magI, Rect(cx, cy, cx, cy)); // Bottom-Right
Mat tmp; // swap quadrants (Top-Left with Bottom-Right)
q0.copyTo(tmp);
q3.copyTo(q0);
tmp.copyTo(q3);
q1.copyTo(tmp); // swap quadrant (Top-Right with Bottom-Left)
q2.copyTo(q1);
tmp.copyTo(q2);
}
Mat DFT2(Mat I)
{
Mat padded; //expand input image to optimal size
int m = getOptimalDFTSize( I.rows );
int n = getOptimalDFTSize( I.cols ); // on the border add zero values
copyMakeBorder(I, padded, 0, m - I.rows, 0, n - I.cols, BORDER_CONSTANT, Scalar::all(0));
Mat planes[] = {Mat_<float>(padded), Mat::zeros(padded.size(), CV_32F)};
Mat complexI;
merge(planes, 2, complexI); // Add to the expanded another plane with zeros
dft(complexI, complexI); // this way the result may fit in the source matrix
// compute the magnitude and switch to logarithmic scale
// => log(1 + sqrt(Re(DFT(I))^2 + Im(DFT(I))^2))
split(complexI, planes); // planes[0] = Re(DFT(I), planes[1] = Im(DFT(I))
magnitude(planes[0], planes[1], planes[0]);// planes[0] = magnitude
Mat magI = planes[0];
magI += Scalar::all(1); // switch to logarithmic scale
log(magI, magI);
// crop the spectrum, if it has an odd number of rows or columns
magI = magI(Rect(0, 0, magI.cols & -2, magI.rows & -2));
// rearrange the quadrants of Fourier image so that the origin is at the image center
int cx = magI.cols/2;
int cy = magI.rows/2;
Mat q0(magI, Rect(0, 0, cx, cy)); // Top-Left - Create a ROI per quadrant
Mat q1(magI, Rect(cx, 0, cx, cy)); // Top-Right
Mat q2(magI, Rect(0, cy, cx, cy)); // Bottom-Left
Mat q3(magI, Rect(cx, cy, cx, cy)); // Bottom-Right
Mat tmp; // swap quadrants (Top-Left with Bottom-Right)
q0.copyTo(tmp);
q3.copyTo(q0);
tmp.copyTo(q3);
q1.copyTo(tmp); // swap quadrant (Top-Right with Bottom-Left)
q2.copyTo(q1);
tmp.copyTo(q2);
normalize(magI, magI, 0, 1, CV_MINMAX); // Transform the matrix with float values into a
// viewable image form (float between values 0 and 1).
return complexI;
}