HPOF:3D Human Pose Recovery from Monocular Video with Optical Flow

This paper introduces HPOF, a novel deep neural network to reconstruct the 3D human motion from a monocular video. Recently, model-based methods have been proposed to simplify the reconstruction task by estimating several parameters that control a deformable surface model to fit the person in the image. However, learning the parameters from a single image is a highly ill-posed problem, and the process is ultimately data-hungry. Existing 3D datasets are not sufficient, and the usage of 2D in-the-wild datasets is often susceptible to the inadequate precision of manual annotations. To address the above issues, our method yields substantial improvements in two domains. First, we leverage optical flow to supervise the 2D rendered images of predicted SMPL models to learn short-term temporal features. Besides, taking long-term temporal consistency into account, we define a novel temporal encoder based on a dilated convolutional network. The encoder decomposes the learning process of human shape and pose, first guarantees the invariance of the body shape, and then simulates a more reasonable forward kinematics process on this basis to achieve more accurate pose estimation. In addition, an adversarial learning framework is applied to supervise the reconstruction progress in a coarse-grained way. We show that HPOF not only improves the accuracy of 3D poses but ensures the realistic body structure throughout the video. We perform extensive experimentation to demonstrate the superiority of our method and analyze the effectiveness of our model, surpassing other state-of-the-arts.