Towards Effective Rotation Generalization in UAV Object Re-Identification

Abstract

UAV surveillance offers a unique aerial perspective, enabling the monitoring of large areas and capturing targets from angles that fixed ground cameras cannot achieve. UAV-based object re-identification (ReID) differs from the extensively studied city camera scenarios, as it involves identifying specific objects in aerial images captured from a dynamic bird’s-eye view. The challenge lies in the significant variation in object perspectives and the often uncertain rotational changes captured by UAVs. Existing ReID methods designed for city cameras struggle to adapt to these rotational variations. To address these challenges, we propose a Transformer-based learnable rotation generalization enhancement method specifically for UAV-based ReID. To improve the model’s adaptability to uncertain rotational changes, we introduce a learnable feature-level rotation simulation technique that generates multiple rotated features. Building on this, we design a rotation diversification loss to decorrelate different rotated features, ensuring a rich feature representation. Additionally, to mitigate the negative effects of image-level rotation augmentation, we propose instance-level and distribution-level rotation invariance regularization. This approach establishes explicit associations between images and their rotated counterparts, facilitating the learning of visually consistent rotation-invariant features. Instance-level constraints ensure that detailed features remain consistent during rotation, while distribution-level constraints maintain the model’s semantic understanding. Notably, our method demonstrates strong versatility, covering a wide range of objects, including persons, vehicles, and various animals. Evaluations on multiple UAV-collected person and vehicle ReID datasets, as well as several animal datasets, consistently show outstanding performance, underscoring its robustness and adaptability to the unique challenges posed by UAV-based ReID.