“…Many methods have been proposed to estimate absolute camera pose, i.e., the position and orientation, such as the perspective-n-point (PnP) solver [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ], which uses n known 2D–3D point correspondences. Pose estimation is one of the key steps in computer vision [ 2 , 10 , 11 ], photogrammetry [ 3 , 11 , 12 ], augmented reality (AR) [ 4 , 13 , 14 , 15 ], structure from motion (SfM) [ 4 , 14 , 16 ], multi-view 3D reconstruction [ 17 , 18 ], and simultaneous localization and mapping (SLAM) [ 4 , 8 , 13 , 19 ]. The absolute pose of a fully uncalibrated camera pose contains six unknown parameters, and each 2D–3D point correspondence gives two constraints [ 20 ], which means that the P3P is the minimal subset to determine the camera pose if the position and orientation are both unknown [ 10 , 21 , 22 , 23 , 24 ].…”