Process and system for video spoof detection based on liveness evaluation

A process for determining a video of a biometric characteristic as being a spoof or a genuine recording of a live biometric characteristic, wherein the video comprises a temporal sequence of frames (j), the process being implemented in a system comprising a processing unit, characterized in that it comprises the steps of:

• preprocessing the video, said preprocessing comprising aligning the biometric characteristic on each frame of the video,
• determining a liveness score of the video, said determination comprising, for each frame of a plurality of frames:
• computing a difference between a motion intensity of a current frame and a motion intensity of each frame of a set of preceding frames,
• inferring, from said differences, a differential motion intensity of the current frame,
• inferring from the differential motion intensities of the plurality of frames a motion intensity of the video,
• comparing said motion intensity to a predetermined threshold, and assigning a liveness score to the video, depending on a the-comparison of the motion intensity of the video with the threshold, and
• according to the liveness scores of the video, determining whether the video is a genuine recording of a biometric characteristic or a spoof.