To address the challenging task of instance-aware human part parsing, a new
bottom-up regime is proposed to learn category-level human semantic
segmentation as well as multi-person pose estimation in a joint and end-to-end
manner. It is a compact, efficient and powerful framework that exploits
structural information over different human granularities and eases the
difficulty of person partitioning. Specifically, a dense-to-sparse projection
field, which allows explicitly associating dense human semantics with sparse
keypoints, is learnt and progressively improved over the network feature
pyramid for robustness. Then, the difficult pixel grouping problem is cast as
an easier, multi-person joint assembling task. By formulating joint association
as maximum-weight bipartite matching, a differentiable solution is developed to
exploit projected gradient descent and Dykstra's cyclic projection algorithm.
This makes our method end-to-end trainable and allows back-propagating the
grouping error to directly supervise multi-granularity human representation
learning. This is distinguished from current bottom-up human parsers or pose
estimators which require sophisticated post-processing or heuristic greedy
algorithms. Experiments on three instance-aware human parsing datasets show
that our model outperforms other bottom-up alternatives with much more
efficient inference.

本论文提出了一种新的底部向上体系结构，以联合学习类别级人类语义分割和多人姿态估计来解决实例感知的人体部位解析的挑战任务。该框架利用不同人类细粒度上的结构信息，使人员分区的难度降低。通过将联合关联建模为最大权二分匹配，实现了可微分的解决方案，从而使我们的方法具有端到端的可训练性，并且允许将分组误差直接传播到多层次的人类表征学习中。