Overview of 3D Human Pose Estimation

3D human pose estimation is a major focus area in the field of computer vision, which plays an important role in practical applications. This article summarizes the framework and research progress related to the estimation of monocular RGB images and videos. An overall perspective of methods integrated with deep learning is introduced. Novel image-based and video-based inputs are proposed as the analysis framework. From this viewpoint, common problems are discussed. The diversity of human postures usually leads to problems such as occlusion and ambiguity, and the lack of training datasets often results in poor generalization ability of the model. Regression methods are crucial for solving such problems. Considering image-based input, the multi-view method is commonly used to solve occlusion problems. Here, the multi-view method is analyzed comprehensively. By referring to video-based input, the human prior knowledge of restricted motion is used to predict human postures. In addition, structural constraints are widely used as prior knowledge. Furthermore, weakly supervised learning methods are studied and discussed for these two types of inputs to improve the model generalization ability. The problem of insufficient training datasets must also be considered, especially because 3D datasets are usually biased and limited. Finally, emerging and popular datasets and evaluation indicators are discussed. The characteristics of the datasets and the relationships of the indicators are explained and highlighted. Thus, this article can be useful and instructive for researchers who are lacking in experience and find this field confusing. In addition, by providing an overview of 3D human pose estimation, this article sorts and refines recent studies on 3D human pose estimation. It describes kernel problems and common useful methods, and discusses the scope for further research.