毛星云opencv之5.5.8离散傅里叶变换程序

本文主要是介绍毛星云opencv之5.5.8离散傅里叶变换程序，对大家解决编程问题具有一定的参考价值，需要的程序猿们随着小编来一起学习吧！

#include <opencv2/opencv.hpp>
#include<opencv2/core/core.hpp>
#include"opencv2/highgui/highgui.hpp"
#include<opencv2/imgproc/imgproc.hpp>
#include<iostream>
using namespace std;
using namespace cv;

int main()
{
Mat srcImage = imread("C:/Users/离子键/source/repos/Project8/1.jpg",0);
imshow("原始图像", srcImage);

int m = getOptimalDFTSize(srcImage.rows);
int n = getOptimalDFTSize(srcImage.cols);

Mat padded;
copyMakeBorder(srcImage, padded, 0, m - srcImage.rows, 0, n - srcImage.cols, BORDER_CONSTANT, Scalar::all(0));

   Mat planes[] = { Mat_<float>(padded),Mat::zeros(padded.size(),CV_32F) };
   Mat complexI;
   merge(planes,2,complexI);

dft(complexI, complexI);

   split(complexI, planes);
   //planes[0] = Re(DFT(I), planes[1] = Im(DFT(I));
   //planes[0] = magnitude
   //Mat magnitudeImage = planes[0];
   magnitude(planes[0], planes[1], planes[0]);// planes[0] = magnitude
   Mat magnitudeImage = planes[0];

magnitudeImage += Scalar::all(1);
log(magnitudeImage, magnitudeImage);

   magnitudeImage = magnitudeImage(Rect(0,0, magnitudeImage.cols&-2, magnitudeImage.rows&-2));
   int cx = magnitudeImage.cols / 2;
   int cy = magnitudeImage.rows / 2;
   Mat q0(magnitudeImage,Rect(0,0,cx,cy));
   Mat q1(magnitudeImage, Rect(cx, 0, cx, cy));
   Mat q2(magnitudeImage, Rect(0, cy, cx, cy));
   Mat q3(magnitudeImage, Rect(cx, cy, cx, cy));

   Mat tmp;
   q0.copyTo(tmp);
   q3.copyTo(q0);
   tmp.copyTo(q3);

   q1.copyTo(tmp);
   q2.copyTo(q1);
   tmp.copyTo(q2);

normalize(magnitudeImage, magnitudeImage,0,1,NORM_MINMAX);

   imshow("频谱幅值", magnitudeImage);
   waitKey();
   return 0;
}

运行结果如图：