You Should Look at All Objects

Understand

Feature pyramid network (FPN) is one of the key components for object detectors.

• However, there is a long-standing puzzle for researchers that the detection performance of large-scale objects are usually suppressed after introducing FPN.
• To this end, this paper first revisits FPN in the detection framework and reveals the nature of the success of FPN from the perspective of optimization.
• Then, we point out that the degraded performance of large-scale objects is due to the arising of improper back-propagation paths after integrating FPN.