Towards Real-Time Person Search with Invariant Feature Learning

Person search aims to locate a query person in a gallery of unconstrained scene images, which has many real-world applications. However, existing methods directly build off of advances in object detection for better performance rather than efficiency. Complex designs in heavy-weight detectors are redundant for person search. Furthermore, challenges in person search force existing methods to employ additional modules, which greatly deteriorates models' efficiency. In this paper, we propose a novel real-time framework for both effective and efficient person search, termed as InvarPS. InvarPS optimizes the over-designed network with invariant feature learning. Specifically, considering the main challenges (i.e., appearance changes, scale variations, and conflicting tasks) in person search, we propose an improved backbone, a Single-Scale Feature Fusion (SSFF) module and a Hierarchical Decoupling Head (HDH) to facilitate the model learning appearance, scale, and task invariant features, respectively. Extensive experiments demonstrate that our method achieves state-of-the-art performance with real-time speed (>100 FPS), which is significantly faster than any previous competitive approach.