  Human hand actions are quite complex, especially when they involve object
manipulation, mainly due to the high dimensionality of the hand and the vast
action space that entails. Imitating those actions with dexterous hand models
involves different important and challenging steps: acquiring human hand
information, retargeting it to a hand model, and learning a policy from
acquired data. In this work, we capture the hand information by using a
state-of-the-art hand pose estimator. We tackle the retargeting problem from
the hand pose to a 29 DoF hand model by combining inverse kinematics and PSO
with a task objective optimisation. This objective encourages the virtual hand
to accomplish the manipulation task, relieving the effect of the estimator's
noise and the domain gap. Our approach leads to a better success rate in the
grasping task compared to our inverse kinematics baseline, allowing us to
record successful human demonstrations. Furthermore, we used these
demonstrations to learn a policy network using generative adversarial imitation
learning (GAIL) that is able to autonomously grasp an object in the virtual
space.
