Edge Wasserstein Distance Loss for Oriented Object Detection
This work addresses regression loss design for oriented object detection, offering a domain-specific improvement for computer vision applications.
The paper tackles the problem of metric discontinuity and square-like issues in oriented object detection by proposing a novel Edge Wasserstein Distance (EWD) loss, which uses edge-based distributions and achieves effective results across multiple datasets and detectors.
Regression loss design is an essential topic for oriented object detection. Due to the periodicity of the angle and the ambiguity of width and height definition, traditional L1-distance loss and its variants have been suffered from the metric discontinuity and the square-like problem. As a solution, the distribution based methods show significant advantages by representing oriented boxes as distributions. Differing from exploited the Gaussian distribution to get analytical form of distance measure, we propose a novel oriented regression loss, Wasserstein Distance(EWD) loss, to alleviate the square-like problem. Specifically, for the oriented box(OBox) representation, we choose a specially-designed distribution whose probability density function is only nonzero over the edges. On this basis, we develop Wasserstein distance as the measure. Besides, based on the edge representation of OBox, the EWD loss can be generalized to quadrilateral and polynomial regression scenarios. Experiments on multiple popular datasets and different detectors show the effectiveness of the proposed method.