Patent ID: 7050607

Claim:
A computer-implemented face detection process for detecting a person's face in an input image and identifying a face pose range into which the face pose exhibited by the detected face falls, comprising using a computer to perform the following process actions: creating a database comprising a plurality of training feature characterizations, each of which characterizes the face of a person at a known face pose or a non-face; training a plurality of detectors arranged in a pyramidal architecture comprising three detector layers and wherein said first detector layer comprises a single full-view detector responsible for the full range of −90 to 90 degrees of face pose, with 0 degrees being frontal view; said second detector layer comprises a first, second and third detector, said first detector being capable of detecting face pose ranges of −90 to 40 degrees, said second detector being capable of detecting face pose ranges of −30 to 30 degrees, and said third detector being capable of detecting face pose range of 40 to 90 degrees; said third detector layer comprising nine detectors, capable of detecting face pose ranges of −90 to −80 degrees, −70 to −60 degrees, −50 to −40 degrees, −30 to −20 degrees, −10 to 10 degrees, 20 to 30 degrees, 40 to 50 degrees, 60 to 70 degrees, and 80 to 90 degrees, respectively, to determine whether a portion of an input image depicts a person's face having a face pose falling within a face pose range associated with one of the detectors using the training feature characterizations; and wherein said detectors using a greater number of feature characterizations are arranged at the bottom of the pyramid, and wherein said detectors arranged to detect finer ranges of face pose are arranged at the bottom of the pyramid; inputting a portion of an input image into the plurality of detectors arranged in a pyramid architecture; and interpreting the output of the plurality of detectors to determine whether the portion of the input image contains a face and if so to identify the pose associated with each detected face.