Keypoints Definition

  1. Keypoints definition
    1. OpenPose
    2. SMPL
  2. Conversion

Keypoints definition

OpenPose

We mainly use the keypoints defined by OpenPose1, including body, hand and face.

name  
body body
hand hand
face face

SMPL

SMPL2 model is used for parametric human body model. We use the 24 body keypoints defined by SMPL.

name  
SMPL body

Conversion

During the fitting process, we use a J_regressor to convert SMPL vertices to OpenPose keypoints. The J_regressor is defined as a matrix \(J\in\mathbb{R}^{25\times 6890}\).

  1. Cao, Z., Hidalgo, G., Simon, T., Wei, S.E., Sheikh, Y.: Openpose: real-time multi-person 2d pose estimation using part affinity fields. arXiv preprint arXiv:1812.08008 (2018) ↩

  2. Loper, Matthew, et al. “SMPL: A skinned multi-person linear model.” ACM transactions on graphics (TOG) 34.6 (2015): 1-16. ↩