Apple granted patent for face biometrics occlusion assessment
A patent newly granted to Apple reveals a method for using ‘heat maps’ to biometrically identify and authenticate a Face ID user whose face is blocked by an object like a mask or their hair.
The patent for ‘Occlusion detection for facial recognition processes’ was awarded by the U.S. Patent and Trademark Office (USPTO), and describes heat maps estimating the location of facial features (or “landmarks”) like the user’s eyes, mouth and nose. The heat map can also include values to represent facial regions that are occluded, and use it in combination with the estimated feature locations to assess landmark occlusion by overlaying the occlusion heat map onto the map if features.
That assessment can in turn be applied to control biometric authentication or other operations. The patent document says occlusion assessments above a certain threshold would prompt the system to discard the image, preventing the device from being unlocked with biometrics.
Apple’s facial recognition-based device unlocking has prevented Face ID for working, prompting the company to implement workarounds.
The document describes the image analyzed to generate the heat map being captured by an array of sensors which may be infrared or RGB sensors.
If implemented in future mobile devices from Apple, the system described could push biometric authentication to a different native modality, like an in-display fingerprint sensor, based on a recently published patent application and widespread speculation that the feature will eventually be included in iPhones.