ffttools.hpp

/*
Author: Christian Bailer
Contact address: Christian.Bailer@dfki.de
Department Augmented Vision DFKI

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*/

#pragma once

//#include <cv.h>

#ifndef _OPENCV_FFTTOOLS_HPP_
#define _OPENCV_FFTTOOLS_HPP_
#endif

//NOTE: FFTW support is still shaky, disabled for now.
/*#ifdef USE_FFTW
#include <fftw3.h>
#endif*/

namespace FFTTools
{



	cv::Mat fftd(cv::Mat img, bool backwards = false, bool byRow = false)
{

    if (img.channels() == 1)
    {
        cv::Mat planes[] = {cv::Mat_<float> (img), cv::Mat_<float>::zeros(img.size())};
        //cv::Mat planes[] = {cv::Mat_<double> (img), cv::Mat_<double>::zeros(img.size())};
        cv::merge(planes, 2, img);
    }
    if(byRow)
      cv::dft(img, img, (cv::DFT_ROWS | cv::DFT_COMPLEX_OUTPUT));
    else
      cv::dft(img, img, backwards ? (cv::DFT_INVERSE | cv::DFT_SCALE) : 0 );

    return img;



}

cv::Mat real(cv::Mat img)
{
    std::vector<cv::Mat> planes;
    cv::split(img, planes);
    return planes[0];
}

cv::Mat imag(cv::Mat img)
{
    std::vector<cv::Mat> planes;
    cv::split(img, planes);
    return planes[1];
}

cv::Mat magnitude(cv::Mat img)
{
    cv::Mat res;
    std::vector<cv::Mat> planes;
    cv::split(img, planes); // planes[0] = Re(DFT(I), planes[1] = Im(DFT(I))
    if (planes.size() == 1) res = cv::abs(img);
    else if (planes.size() == 2) cv::magnitude(planes[0], planes[1], res); // planes[0] = magnitude
    else assert(0);
    return res;
}

cv::Mat complexMultiplication(cv::Mat a, cv::Mat b, bool conj = false)
{
    std::vector<cv::Mat> pa;
    std::vector<cv::Mat> pb;
    cv::split(a, pa);
    cv::split(b, pb);

	if (conj)
		pb[1] *= -1.0;

    std::vector<cv::Mat> pres;
    pres.push_back(pa[0].mul(pb[0]) - pa[1].mul(pb[1]));
    pres.push_back(pa[0].mul(pb[1]) + pa[1].mul(pb[0]));

    cv::Mat res;
    cv::merge(pres, res);

    return res;
}

cv::Mat complexDivisionReal(cv::Mat a, cv::Mat b)
{
    std::vector<cv::Mat> pa;
    cv::split(a, pa);

    std::vector<cv::Mat> pres;

    cv::Mat divisor = 1. / b;

    pres.push_back(pa[0].mul(divisor));
    pres.push_back(pa[1].mul(divisor));

    cv::Mat res;
    cv::merge(pres, res);
    return res;
}

cv::Mat complexDivision(cv::Mat a, cv::Mat b)
{
    std::vector<cv::Mat> pa;
    std::vector<cv::Mat> pb;
    cv::split(a, pa);
    cv::split(b, pb);

    cv::Mat divisor = 1. / (pb[0].mul(pb[0]) + pb[1].mul(pb[1]));

    std::vector<cv::Mat> pres;

    pres.push_back((pa[0].mul(pb[0]) + pa[1].mul(pb[1])).mul(divisor));
    pres.push_back((pa[1].mul(pb[0]) + pa[0].mul(pb[1])).mul(divisor));

    cv::Mat res;
    cv::merge(pres, res);
    return res;
}

void rearrange(cv::Mat &img)
{
    // img = img(cv::Rect(0, 0, img.cols & -2, img.rows & -2));
    int cx = img.cols / 2;
    int cy = img.rows / 2;

    cv::Mat q0(img, cv::Rect(0, 0, cx, cy)); // Top-Left - Create a ROI per quadrant
    cv::Mat q1(img, cv::Rect(cx, 0, cx, cy)); // Top-Right
    cv::Mat q2(img, cv::Rect(0, cy, cx, cy)); // Bottom-Left
    cv::Mat q3(img, cv::Rect(cx, cy, cx, cy)); // Bottom-Right

    cv::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);
}
/*
template < typename type>
cv::Mat fouriertransFull(const cv::Mat & in)
{
    return fftd(in);

    cv::Mat planes[] = {cv::Mat_<type > (in), cv::Mat_<type>::zeros(in.size())};
    cv::Mat t;
    assert(planes[0].depth() == planes[1].depth());
    assert(planes[0].size == planes[1].size);
    cv::merge(planes, 2, t);
    cv::dft(t, t);

    //cv::normalize(a, a, 0, 1, CV_MINMAX);
    //cv::normalize(t, t, 0, 1, CV_MINMAX);

    // cv::imshow("a",real(a));
    //  cv::imshow("b",real(t));
    // cv::waitKey(0);

    return t;
}*/

void normalizedLogTransform(cv::Mat &img)
{
    img = cv::abs(img);
    img += cv::Scalar::all(1);
    cv::log(img, img);
    // cv::normalize(img, img, 0, 1, CV_MINMAX);
}

typedef std::vector<cv::Mat> ComplexMats;

ComplexMats MultiChannelsDFT(const cv::Mat &img, int flags = 0)
{
	std::vector<cv::Mat> chls;
	std::vector<cv::Mat> out;
	cv::split(img, chls);
	out.resize(chls.size());
	for (int i = 0; i < chls.size(); i++)
	{
		cv::dft(chls[i], out[i], cv::DFT_COMPLEX_OUTPUT);
		//out[i] = (out[i]);
	}
	// cv::Mat out_m;
	// cv::merge(out, out_m);
	return out;
}

ComplexMats ComplexMatsMultiMat(const ComplexMats &A, cv::Mat b)
	{
		
		ComplexMats out;
		out.resize(A.size());
		for (int i = 0; i < A.size(); i++)
		{
			out[i] = complexMultiplication(b, A[i]);
		}
		return out;
	}


ComplexMats ComplexMatsMultiComplexMats(const ComplexMats &A, const ComplexMats &B)
{

	ComplexMats out;
	assert(A.size() == B.size());
	out.resize(A.size());
	for (int i = 0; i < A.size(); i++)
	{
		out[i] = complexMultiplication(A[i], B[i]);
	}
	return out;
}

     ComplexMats MCComplexConjMultiplication(const ComplexMats &A)
	{

		ComplexMats out;
		out.resize(A.size());
		for (int i = 0; i < A.size(); i++)
		{
			out[i] = (complexMultiplication(A[i], A[i], true));
		}
		//cv::Mat out_m;
		//cv::merge(out, out_m);
		return out;
	}

	cv::Mat MCMulti(cv::Mat a, cv::Mat b)
	{
		std::vector<cv::Mat> pa;
		cv::split(a, pa);

		std::vector<cv::Mat> pres;

		pres.resize(pa.size());

		for (int i = 0; i < pa.size(); i++)
			pres[i] = pa[i].mul(b);
		cv::Mat res;
		cv::merge(pres, res);

		return res;
	}


	cv::Mat MCSum(const ComplexMats &a)
	{
		//std::vector<cv::Mat> pa;
		//cv::split(a, pa);
		assert(a.size() != 0);
		cv::Mat out;
		a[0].copyTo(out);
		for (int i = 1; i < a.size(); i++)
			out = out + a[i];

		return out;
	}

	cv::Mat MCSum(const cv::Mat &a)
	{
		std::vector<cv::Mat> pa;
		cv::split(a, pa);
		assert(pa.size() != 0);
		cv::Mat out;
		pa[0].copyTo(out);
		for (int i = 1; i < pa.size(); i++)
			out = out + pa[i];

		return out;
	}

}