I'm trying to implement fftshift from matlab for OpenCV. Can you please review the correctness of my algorithm? Have I missed something? Also, is there a better and faster way to do it?
cv::Mat ff;
cv::dft(distanceF, ff, cv::DFT_COMPLEX_OUTPUT);
//Make place for both the complex and the real values
cv::Mat planes[] = {cv::Mat::zeros(distanceF.size(),1, CV_32F), cv::Mat::zeros(distanceF.size(),1, CV_32F)};
cv::split(ff, planes); // planes[0] = Re(DFT(I), planes[1] = Im(DFT(I))
cv::vector<float> im(planes[1].cols);
cv::vector<float> re(planes[0].cols);
int m = planes[0].cols;
int p = ceil(m/2);
for (int i = 0; i < p; i++)
{
im[i] = planes[1].at<float>(p + i +1);
im[p +i +1] = planes[1].at<float>(i +1);
re[i] = planes[0].at<float>(p + i +1);
re[p +i +1] = planes[0].at<float>(i +1);
}
im[p] = planes[1].at<float>(0);
re[p] = planes[0].at<float>(0);
cv::Mat input[] = {cv::Mat(im),cv::Mat(re)};
cv::merge(input,2,ff);
