c_cpp mat to dlib to eigen

Posted 2021-05-14

#define _USE_MATH_DEFINES
#include <opencv2/opencv.hpp>
#include <Eigen/Geometry>
#include <dlib/matrix.h>
#include <dlib/opencv.h>
#include <dlib/image_transforms.h>

using namespace cv;

int main(int argc, char **argv)
{
	// Set up a movement
	Eigen::Matrix4d M1;
	M1 << 1, 0, 0, 0, //
		0, 1, 0, 0, //
		0, 0, 1, 0, //
		0, 0, 0, 1;

	Eigen::Matrix4d M2;
	double theta = M_PI / 2;
	M2 << cos(theta), -sin(theta), 0, 0, //
		sin(theta), cos(theta), 0, 0, //
		0, 0, 1, 1, //
		0, 0, 0, 1;

	Eigen::Affine3d T1(M1);
	Eigen::Affine3d T2(M2);

	// Compute essential
	Eigen::Affine3d T_CW = T2.inverse() * T1;
	Eigen::Vector3d t = T_CW.translation();
	Eigen::Matrix3d R = T_CW.rotation();

	std::cout << "delta transform" << std::endl;
	std::cout << dlib::mat(t) << std::endl;
	std::cout << dlib::mat(R) << std::endl;

	Mat tx;
	tx = (Mat_<double>(3, 3) << 0, -t(2), t(1), //
		t(2), 0, -t(0), //
		-t(1), t(0), 0);

	Mat Rx = (Mat_<double>(3, 3) << R(0, 0), R(0, 1), R(0, 2), //
		R(1, 0), R(1, 1), R(1, 2), //
		R(2, 0), R(2, 1), R(2, 2));

	Mat E = tx * Rx;
	dlib::array2d<double> E_tmp;
	//dlib::assign_image(E_tmp, E);

	//std::cout << "E" << std::endl << mat(E_tmp) << std::endl;		

	// recover essential
	Mat R1;
	Mat R2;
	Mat tcv;
	decomposeEssentialMat(E, R1, R2, tcv);

	std::cout << "decomposed matrix" << std::endl;
	std::cout << "R1" << std::endl << R1 << std::endl;
	std::cout << "R2" << std::endl << R2 << std::endl;
	std::cout << "t" << std::endl << tcv << std::endl;

}