“…We assume all the keypoints are parallel to the AruCo marker board, which is defined as the XY plane in the AruCo markers coordinate. To compensate for the thickness of the hand, we set the Z value of each keypoint to be 1.15 cm as the mean of human hand thickness is 2.3 cm (ChenChen et al , 2011). Then, the 3D positions of hand keypoints
Pihand3d=true[Xi,Yi,Z=1.15true],i=1…66 in AruCo markers coordinate can be calculated as below: where
pihand2d=true[ui,vitrue], i=1,…,66 denotes the 2D positions of hand keypoints in image coordinates; K denotes camera intrinsic parameters; and s is a scale factor.…”