convert from fundamental matrix to camera pose (R1, R2, T) in OpenCV2 (similar to decomposeEssentialMat() in OpenCV 3)

decompose_fmatrix.cpp

/*
  you can use the result matrix (rot1,rot2,tvec) as:
    candidate1: rot1, tvec
    candidate2: rot1, -tvec
    candidate3: rot2, tvec
    candidate4: rot2, -tvec
*/
bool convertF2RT(Mat &F,Mat &K,Mat &rot1,Mat &rot2,Mat &tvec) {
  if (F.empty() || K.empty()) return false;

  Mat Kt;
  transpose(K,Kt);
  SVD svd(Kt*F*K,SVD::MODIFY_A);
  Mat W = (Mat_<double>(3,3) << 0,-1,0,1,0,0,0,0,1);
  Mat Wt = (Mat_<double>(3,3) << 0,1,0,-1,0,0,0,0,1);
  rot1 = svd.u * W * svd.vt;
  rot2 = svd.u * Wt * svd.vt;
  svd.u.col(2).copyTo(tvec);

  return true;
}