Face liveness detection by focusing on frontal faces and image backgrounds

Face recognition systems have been deployed in many security applications nowadays. Its popularity attracts the attention of an adversary. One of the common methods is to show a photo or video in front of the camera to mislead the detection of the system. In this paper, we propose a face liveness detection method by investigating the focus distance between the face and the background. The focus distance should be the same for the photo or video, while the distance should be different for a real person. The experimental results illustrate that the performance of the detection is improved significantly by using our method in comparison with the one considering the focus distance between the nose and the ear.