Anti-Spoofing

Non-transitory computer-readable storage media including computer-readable instructions, which when executed on one or more processors of a user verification processing system, cause the system to carry out the following:

• receiving image data of at least one verification image as captured by an image capture device of a fixed computer terminal at a time corresponding to a request for access to a restricted function of the fixed computer terminal;
• and
• in response to the access request, applying user verification to determine whether to grant access to the restricted function of the fixed computer terminal, by:
• determining, by a differential feature extractor, a differential feature descriptor encoding feature differences between the verification image data and image data of at least one unobstructed background image as captured by the image capture device,
• processing, by an anti-spoofing classifier, the differential feature descriptor to classify it in relation to real and spoofing classes corresponding, respectively, to verification images of actual humans and verification images of spoofing entities, and
• granting or refusing access to the restricted function of the fixed computer terminal based on the classification of the differential feature descriptor by the anti-spoofing classifier.

A user verification processing system comprising:

• an image input configured to receive image data captured by an image capture device of a fixed computer terminal;
• and
• one or more processors configured to verify a user of the fixed computer terminal by at least:
• receiving image data of at least one verification image as captured by an image capture device of the fixed computer terminal at a time corresponding to a request for access to a restricted function of the fixed computer terminal;
• and
• in response to the access request, applying user verification to determine whether to grant access to the restricted function of the fixed computer terminal, by:
• determining, by a differential feature extractor, a differential feature descriptor encoding feature differences between the verification image data and image data of at least one unobstructed background image as captured by the image capture device,
• processing, by an anti-spoofing classifier, the differential feature descriptor to classify it in relation to real and spoofing classes corresponding, respectively, to verification images of actual humans and verification images of spoofing entities, and
• granting or refusing access to the restricted function of the fixed computer terminal based on the classification of the differential feature descriptor by the anti-spoofing classifier.