This document discusses the development of a face mask detection system using YOLOv4. The system uses a deep learning model with YOLOv4 to detect faces in real-time video and determine if each person is wearing a mask or not. It is trained on images of faces with and without masks. The model uses CSPDarknet53 as the backbone network and PANet for feature aggregation. It is implemented with OpenCV and a Python GUI for a user interface. The goal is to help enforce mask mandates and alert authorities if too many people in an area are not wearing masks.