Today the U.S. Patent and Trademark Office officially granted Apple a patent that relates to advancing Face ID with the use of heat maps to assess occlusion of landmarks on a user's face in a captured image.
Biometric authentication processes are being used more frequently to allow users to more readily access their devices without the need for passcode or password authentication. One example of a biometric authentication process is fingerprint authentication using a fingerprint sensor. Facial recognition is another biometric process that may be used for authentication of an authorized user of a device. Facial recognition processes are generally used to identify individuals in an image and/or compare individuals in images to a database of individuals to match the faces of individuals.
In some cases, an image captured of a user during a facial recognition process (e.g., either an enrollment process or an authentication process) may include at least some occlusion of the user in the image. Occlusion of the user includes the blocking or obscuring of the user (e.g., the face of the user or some portion of the user's face) by some object (e.g., a finger, a hand, hair, masks, scarfs, etc.) in the image. Occlusion of the user in captured images may reduce the effectiveness of processing the image in the facial recognition process.
Landmark and occlusion heat maps may be generated and used to assess occlusion of landmarks on a user's face in a captured image. Landmark heat maps may be grid representations of the user's face that are used to estimate the location of landmarks on the user's face in the captured image. The occlusion heat map may be a grid representation of the user's face that includes scaled values representing the amount of occlusion in the regions of the grid.
The estimated locations of the landmarks may be used in combination with the occlusion heat map to determine if and how much occlusion of the landmarks there may be in the captured image (e.g., an occlusion score for each of the landmarks). Determined values of occlusion for the landmarks may be used to control one or more operations of the device.
Apple's patent FIG. 5 depicts an example of an embodiment of an image input; FIG. 9 depicts an occlusion heat map overlaid onto a map of landmark shapes. You have to enlarge the graphic below in order to see the image of FIG. 9 correctly.
For more details, review Apple's granted patent 10,896,318. Our cover graphic also illustrates patent FIG. 8 depicts a representation of an example of an embodiment of estimated centers of gravity, related to facial heat mapping.