Created
November 7, 2019 08:30
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#include <iostream> | |
#include <opencv2/opencv.hpp> | |
#include <stdint.h> | |
const char* MAIN_WIN = "Main window"; | |
const char* DFT_WIN = "Fourier transform"; | |
void takeDft(cv::Mat& source, cv::Mat& destination) { | |
cv::Mat originalComplex[2] = { source, cv::Mat::zeros(source.size(), CV_32F) }; | |
cv::Mat dftReady; | |
cv::merge(originalComplex, 2, dftReady); | |
cv::Mat dftOfOriginal; | |
cv::dft(dftReady, dftOfOriginal, cv::DFT_COMPLEX_OUTPUT); | |
destination = dftOfOriginal; | |
} | |
void invertDft(cv::Mat& source, cv::Mat& destination) { | |
dft(source, destination, cv::DFT_INVERSE | cv::DFT_REAL_OUTPUT | cv::DFT_SCALE); | |
} | |
void showDft(cv::Mat& source) { | |
cv::Mat splitArray[2] = { cv::Mat::zeros(source.size(), CV_32F), cv::Mat::zeros(source.size(), CV_32F) }; | |
cv::split(source, splitArray); | |
cv::Mat dftMagnitude; | |
cv::magnitude(splitArray[0], splitArray[1], dftMagnitude); | |
dftMagnitude += cv::Scalar::all(1); | |
cv::log(dftMagnitude, dftMagnitude); | |
cv::normalize(dftMagnitude, dftMagnitude, 0, 1, cv::NORM_MINMAX); | |
int centerX = dftMagnitude.cols / 2; | |
int centerY = dftMagnitude.rows / 2; | |
cv::Mat q1(dftMagnitude, cv::Rect(0, 0, centerX, centerY)); | |
cv::Mat q2(dftMagnitude, cv::Rect(centerX, 0, centerX, centerY)); | |
cv::Mat q3(dftMagnitude, cv::Rect(0, centerY, centerX, centerY)); | |
cv::Mat q4(dftMagnitude, cv::Rect(centerX, centerY, centerX, centerY)); | |
cv::Mat swapMap; | |
q1.copyTo(swapMap); | |
q4.copyTo(q1); | |
swapMap.copyTo(q4); | |
q2.copyTo(swapMap); | |
q3.copyTo(q2); | |
swapMap.copyTo(q3); | |
cv::namedWindow(DFT_WIN, cv::WINDOW_FREERATIO); | |
cv::imshow(DFT_WIN, dftMagnitude); | |
} | |
int main(int argv, char** argc) { | |
cv::Mat original = cv::imread("space.jpg", cv::IMREAD_GRAYSCALE); | |
cv::Mat originalFloat; | |
original.convertTo(originalFloat, CV_32FC1, 1.0 / 255.0); | |
cv::Mat dftOfOriginal; | |
takeDft(originalFloat, dftOfOriginal); | |
cv::Mat inverted; | |
invertDft(dftOfOriginal, inverted); | |
cv::namedWindow(MAIN_WIN, cv::WINDOW_FREERATIO); | |
cv::resizeWindow(MAIN_WIN, 1280, 720); | |
cv::moveWindow(MAIN_WIN, 100, 100); | |
showDft(dftOfOriginal); | |
cv::imshow(MAIN_WIN, inverted); | |
cv::waitKey(); | |
} |
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