Real-time and low-memory multi-face detection system design based on naive Bayes classifier using FPGA

In recent years, face detection is widely used in various fields, such as face recognition, image focusing, and surveillance systems. This study proposes a real-time face detection system based on naive Bayesian classifier using Field-programmable gate array(FPGA). The detection system divided into three main parts, feature extraction, candidate face detection, and false elimination. First, downscale the image to the image pyramid and extract local binary image features from each downscaling image; then features go through the naive Bayesian classifier to identify candidate faces. Finally, use skin color filter and face overlapping elimination to remove false positives. Detection results output to the monitor in VGA. In this paper, face detection system to implement in FPGA. As a result of the FPGA parallel processing, in 640×480 resolutions, the face detection of an image executes within 16.7 milliseconds; the improved local binary features, compared to Haar features, save around 140 times the amount of memory. The experimental results show that the accuracy rate is higher than 95% in face detection, which implies the proposed real-time detection system is indeed effective and efficient.