SiamPRN algorithm performs well in visual tracking, but it is easy to drift under occlusion and fast motion scenes because it uses $$\ell _1$$ℓ 1 -smooth loss function to measure the regression location of bounding box. In this paper, we propose a multivariate intersection over union (MIOU) loss in SiamRPN tracking framework. Firstly, MIOU loss includes three geometric factors in regression: the overlap area ratio, the center distance ratio, and the aspect ratio, which can better reflect the coincidence degree of target box and prediction box. Secondly, we improve the definition of aspect ratio loss to avoid gradient explosion, improve the optimization performance of prediction box. Finally, based on SiamPRN tracker, we compared the tracking performance of $$\ell _1$$ℓ 1 -smooth loss, IOU loss, GIOU loss, DIOU loss, and MIOU loss. Experimental results show that the MIOU loss has better target location regression than other loss functions on the OTB2015 and VOT2016 benchmark, especially for the challenges of occlusion, illumination change and fast motion.

Gait recognition is one of the most promising biometric technologies that can identify individuals at a long distance. From observation, we find that there are differences in the length of the gait cycle and the quality of each frame in the sequence. In this paper, we propose a novel gait recognition framework to analyze human gait. On the one hand, we designed the Multi-scale Temporal Aggregation (MTA) module that models temporal and aggregate contextual information with different scales, on the other hand, we introduce the Metric-based Frame Attention Mechanism (MFAM) to re-weight each frame by the importance score, which calculates using the distance between frame-level features and sequence-level features. We evaluate our model on two of the most popular public datasets, CASIA-B and OU-MVLP. For normal walking, the rank-1 accuracies on the two datasets are 97.6% and 90.1%, respectively. In complex scenarios, the proposed method achieves accuracies of 94.8% and 84.9% on CASIA-B under bag-carrying and coat-wearing walking conditions. The results show that our method achieves the top level among state-of-the-art methods.