“…Under a simple live/spoof binary classification settings, resulting two representations separated by a classification boundary can have mixed information, such as subject ID. Several neural networks are proposed to disentangle live/spoof class signature from the unwanted information [48], [49], [50] Because most of the presentation attacks are conducted under visible-light domain, using multimodal input or non-visible modality (e.g., depth, rPPG, SWIR) are useful for increasing PAD performance [6], [51], [52], [53], [54], [55], [56], [57], [58], [59], [60], [61], [62].…”