Compression of Vehicle and Pedestrian Detection Network Based on YOLOv3 Model

Abstract

The commonly used object detection algorithm based on convolutional neural network is difficult to meet the real-time requirement on embedded platform due to its large size of model, large amount of calculation, and long inference time. It is necessary to use model compression to reduce the amount of network calculation and increase the speed of network inference. This paper conducts compression of vehicle and pedestrian detection network by pruning and removing redundant parameters. The vehicle and pedestrian detection network is trained based on YOLOv3 model by using K-means++ to cluster the anchor boxes. The detection accuracy is improved by changing the proportion of categorical losses and regression losses for each category in the loss function because of the unbalanced number of targets in the dataset. A layer and channel pruning algorithm is proposed by combining global channel pruning thresholds and L1 norm, which can reduce the time cost of the network layer transfer process and the amount of computation. Network layer fusion based on TensorRT is performed and inference is performed using half-precision floating-point to improve the speed of inference. Results show that the vehicle and pedestrian detection compression network pruned 84% channels and 15 Shortcut modules can reduce the size by 32% and the amount of calculation by 17%. While the network inference time can be decreased to 21 ms, which is 1.48 times faster than the network pruned 84% channels.