Spoof detection for biometric authentication

A computer-implemented method (600) comprising: obtaining (602, 702) two or more images (310) of a subject, including an eye view (410), wherein the images (310) collectively include a plurality of focus distances; determining (712) a performance metric based on at least one detected movement of the eye (410) when the eye (410) appears in a plurality of images (310), wherein the performance metric is a measurement of the deviation of detected movement and timing of expected eye movement (410); determining (714) a spatial metric based on at least one distance from a sensor (420) to a reference point that appears in a plurality of images (310), each having a different respective focus distance; determining (716) a reflectance metric based on either (i) detected changes in surface glare on a surface of the eye when the eye appears in a plurality of images, measuring a time difference between (i) the appearance of a flash pulse captured by one or more of the images (310) and (ii) the appearance of a corresponding glare detected in the eye (410) in one or more of the images (310); or (ii) detected changes in specular reflection patterns by measuring the uniformity of a glare pattern on an outer surface of the eye (410) visible in one or more of the images (310) caused by one or more flash pulses captured by one or more of the images (310), wherein the uniformity of a glare pattern on the eye (410) is measured as a ratio of the circumference to an area of ​​the glare; where the reflectance metric is a measurement of changes in glare or specular reflection patterns on the surface of the eye, determine (604, 730) a liveliness rating based on the behavioral, spatial, and reflectance metric, reflecting the liveliness rating the probability that the images (310) represent a live eye (410); and reject (608) or accept (610) the two or more images (310) based on the vividness rating, wherein the two or more images (310) are rejected (608) when the vividness rating indicates a low probability live eye (410).