enum { SOLVEPNP_ITERATIVE = 0,
       SOLVEPNP_EPNP      = 1, //!< EPnP: Efficient Perspective-n-Point Camera Pose Estimation @cite lepetit2009epnp
       SOLVEPNP_P3P       = 2, //!< Complete Solution Classification for the Perspective-Three-Point Problem @cite gao2003complete
       SOLVEPNP_DLS       = 3, //!< A Direct Least-Squares (DLS) Method for PnP  @cite hesch2011direct
       SOLVEPNP_UPNP      = 4, //!< Exhaustive Linearization for Robust Camera Pose and Focal Length Estimation @cite penate2013exhaustive
       SOLVEPNP_AP3P      = 5, //!< An Efficient Algebraic Solution to the Perspective-Three-Point Problem @cite Ke17
       SOLVEPNP_MAX_COUNT      //!< Used for count
};

bool solvePnP( InputArray _opoints, InputArray _ipoints,
               InputArray _cameraMatrix, InputArray _distCoeffs,
               OutputArray _rvec, OutputArray _tvec, bool useExtrinsicGuess, int flags )
{ ...

CV_IMPL void cvFindExtrinsicCameraParams2( const CvMat* objectPoints,
                  const CvMat* imagePoints, const CvMat* A,
                  const CvMat* distCoeffs, CvMat* rvec, CvMat* tvec,
                  int useExtrinsicGuess )

CV_IMPL int cvFindHomography( const CvMat* _src, const CvMat* _dst, CvMat* __H, int method,
                              double ransacReprojThreshold, CvMat* _mask, int maxIters,
                              double confidence)

cv::Mat cv::findHomography( InputArray _points1, InputArray _points2,
                            int method, double ransacReprojThreshold, OutputArray _mask,
                            const int maxIters, const double confidence)

CV_IMPL void cvConvertPointsHomogeneous( const CvMat* _src, CvMat* _dst )