Target Capacity Filter Pruning Method for Optimized Inference Time Based on YOLOv5 in Embedded Systems

Recently, convolutional neural networks (CNNs), which exhibit excellent performance in the field of computer vision, have been in the spotlight. However, as the networks become wider for higher accuracy, the number of parameters and the computational costs increase exponentially. Therefore, it is challenging to use deep learning networks in embedded environments with limited resources, computational performance, and power. Moreover, CNNs consume a great deal of time for inference. To solve this problem, we propose a practical method for filter pruning to provide an optimal network architecture for target capacity and inference acceleration. After revealing the correlation between the inference time and the FLOPs, we proposed a method to generate a network with the desired inference time. Various object detection datasets were used to evaluate the performance of the proposed filter pruning method. The inference time of the pruned network was measured and analyzed using the NVIDIA Jetson Xavier NX platform. As a result of pruning the number of parameters and FLOPs of the YOLOv5 network in the PASCAL VOC dataset by 30%, 40%, and 50%, the mAP decreased by 0.6%, 2.3%, and 2.9%, respectively, while the inference time was improved by 14.3%, 26.4%, and 34.5%, respectively.