Multi-sensor fusion is a key technology in the field of autonomous driving and robotics. Traditional offline multi-sensor fusion calibration methods rely on manual operations and fail to meet real-time requirements, while recent online calibration technologies have limited generalization capabilities. This paper proposes CalibMutiL, an end-to-end calibration network that departs from conventional deep feature fusion by leveraging multi-level RGB image features to guide point cloud alignment. CalibMutiL introduces a Multi-level Fusion module (MLF) that effectively utilizes the rich visual features of the image. In addition, we regard the alignment process as a sequence prediction problem and further improve the performance through an Iterative Refinement module (IRM). Evaluation of the KITTI odometry and raw dataset demonstrates the average calibration error reaches 0.81cm and 0.09°. The generalization tests resulted in errors of 4.24cm and 0.13°, outperforming existing methods. Our implementation will be publicly available at https://github.com/VIP-G/CalibMutiL.

The rapid development of Uncrewed Aerial Vehicles (UAVs) and their unique vantage points present both new opportunities and challenges for person Re-Identification (ReID). Uncertain rotations and scale variations of targets in UAV images, coupled with complex environmental factors, hinder existing methods from extracting robust feature representations. Some methods either make minor modifications to the traditional model architecture or apply simple image rotations but still fail to effectively address the challenges of UAV person ReID. To overcome these limitations, we propose a novel Data Augmentation and Rotation Invariance (DARI) algorithm. First, rotation-invariant convolution is introduced to adaptively extract features, mitigating the uncertainty caused by target rotation. Second, a refined data augmentation correction strategy is employed to reduce noise interference by increasing the richness of global features at different stages. Additionally, considering that multiple features of the same identity should yield consistent recognition result, invariant constraints are designed to enhance the clustering effect. We conducted extensive experiments on both UAV and fixed-camera datasets. The results on PRAI-1581 demonstrate a 5.6% and 6.1% improvement in mAP and Rank-1, respectively, compared to baseline. These findings highlight the model’s effectiveness in addressing the challenges of UAV ReID, demonstrating its robustness and superiority.

Abstract The use of deep neural networks has revolutionised object tracking tasks, and Siamese trackers have emerged as a prominent technique for this purpose. Existing Siamese trackers use a fixed template or template updating technique, but it is prone to overfitting, lacks the capacity to exploit global temporal sequences, and cannot utilise multi‐layer features. As a result, it is challenging to deal with dramatic appearance changes in complicated scenarios. Siamese trackers also struggle to learn background information, which impairs their discriminative ability. Hence, two transformer‐based modules, the Spatio‐Temporal Fusion (ST) module and the Discriminative Enhancement (DE) module, are proposed to improve the performance of Siamese trackers. The ST module leverages cross‐attention to accumulate global temporal cues and generates an attention matrix with ST similarity to enhance the template's adaptability to changes in target appearance. The DE module associates semantically similar points from the template and search area, thereby generating a learnable discriminative mask to enhance the discriminative ability of the Siamese trackers. In addition, a Multi‐Layer ST module (ST + ML) was constructed, which can be integrated into Siamese trackers based on multi‐layer cross‐correlation for further improvement. The authors evaluate the proposed modules on four public datasets and show comparative performance compared to existing Siamese trackers.