For biometric authentication, there are several anti-spoofing techniques. From the simplest such as the detection of eye blinking, measuring the intrinsic facial movement (after all, a photo can not blink … although a decontextualized video could also work), even the latest texture analysis techniques combined with user challenges, for example, look for the dilation of the pupil, making the screen darken and then suddenly shine.
However, we must take care with processes that generate friction, causing possible conversion drops. More sophisticated techniques use 3D cameras to search depth information of a 3D face, or infrared cameras to detect thermal information. However, both require special equipment and, therefore, are not compatible with most of the webcams and mobile phone cameras currently available.