SYSTEMS AND METHODS FOR LIVENESS ANALYSIS

摘要

In a system for determining liveness of an image presented for authentication, a reference signal is rendered on a display, and a reflection of the rendered signal from a target is analyzed to determine liveness thereof. The analysis includes spatially and/or temporally band pass filtering the reflected signal, and determining RGB values for each frame in the reflected signal and/or each pixel in one or more frames of the reflected signal. Frame level and/or pixel-by-pixel correlations between the determined RGB values and the rendered signal are computed, and a determination of whether an image presented is live or fake is made using either or both correlations.

主权项

1. A computer-implemented method comprising:
rendering on a display device a time-varying first signal comprising a plurality of different respective signals that are separated in phase from each other; during the rendering, capturing a plurality of images of a target that is illuminated by the rendered first signal; applying a band pass filter temporally to the images to generate a plurality of filtered images; extracting a second signal from the filtered images; generating a first measure based on, at least, a temporal correlation of the first signal and the second signal; for each pixel location in a plurality of pixel locations, extracting a respective signal for the pixel location based on changes to a respective value of the pixel location over time in a plurality of the filtered images; calculating a respective pixel location correlation score for each of the pixel locations based on a correlation of the respective extracted signal of the pixel location to the first signal; generating a second measure based on, at least, a plurality of the pixel location correlation scores; and accepting or rejecting the target based on, at least, the first and second measures.