Domain Contrast for Domain Adaptive Object Detection

Despite of the substantial progress of visual object detection, models trained in one video domain often fail to generalize well to others due to the change of camera configurations, lighting conditions, and object person views. In this paper, we present Domain Contrast (DC), a simple yet effective approach inspired by contrastive learning for training domain adaptive detectors. DC is deduced from the error bound minimization perspective of a transferred model, and is implemented with cross-domain contrast loss which is plug-and-play. By minimizing cross-domain contrast loss, DC transfers detectors across domains while naturally alleviating the class imbalance issue in the target domain. DC can be applied at either image level or region level, consistently improving detectors’ discriminability while maintaining the transferability. Extensive experiments on commonly used benchmarks show that DC improves the baseline and state-of-the-art by significant margins, while demonstrating great potential for large domain divergence. Code is released at https://github.com/PhoneSix/Domain-Contrast.