基本上我试图在灰度图像上实现一个非常基本的Wiener滤波器版本,使用一个精简的Wiener方程:(1 /(SNR))* DFT(Image)之后我采用IDFT整个东西。我的问题是我的输出图像应该被过滤看起来与输入完全一样,因此看起来像素值根本没有变化。谁能告诉我哪里出错了?这是我目前使用的代码:
#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;
}