TYolov5: A Temporal Yolov5 detector based on quasi-recurrent neural networks for real-time handgun detection in video

Abstract

Timely handgun detection is a crucial problem to improve public safety; nevertheless, the effectiveness of many surveillance systems, still depend of finite human attention. Much of the previous research on handgun detection is based on static image detectors, leaving aside valuable temporal information that could be used to improve object detection in videos. To improve the performance of surveillance systems, a real-time temporal handgun detection system should be built. Using Temporal Yolov5, an architecture based in Quasi-Recurrent Neural Networks, temporal information is extracted from video to improve the results of the handgun detection. Moreover, two publicity available datasets are proposed, labeled with hands, guns, and phones. One containing 2199 static images to train static detectors, and another with 5960 frames of videos to train temporal modules. Additionally, we explore two temporal data augmentation techniques based in Mosaic and Mixup. The resulting systems are three real-time architectures: one focused in reducing inference with a mAP(50:95) of 56.1, another in having a good balance between inference and accuracy with a mAP(50:95) of 59.4, and a last one specialized in accuracy with a mAP(50:95) of 60.6. Temporal Yolov5 achieves real-time detection and take advantage of temporal features contained in videos to perform better than Yolov5 in our temporal dataset. Making TYolov5 suitable for real-world applications.