Patent ID: 6671391
Filing Date: 2003-12-30
Classification: G06K

Abstract:
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 of a plurality of training image feature characterizations, each of which represents the face of a person at a known face pose; training a plurality of support vector machines (SVMs), each of which is dedicated to a particular range of face poses, to indicate how closely a region extracted from an input image depicts a person's face exhibiting a face pose falling within the face pose range associated with that SVM, using said training image feature characterizations, which are abstracted so as to represent said images in simpler form for processing wherein said abstraction comprises: deriving a group of image coefficients from each training image that characterize the image in a manner that distinguishes the image from other images depicting faces at a different pose range; and for each training image, selecting among the coefficients of the group of coefficients derived from the training image to form a set of feature vectors, each of which is tailored to a specific face pose range, wherein the same selection criteria is used to select the coefficients associated with training images belonging to the same pose range; training a neural network having inputs which are in communication with the output of each SVM to identify, using the SVM outputs, whether a region extracted from an input image depicts a person's face, and whenever the extracted region is identified as depicting a person's face, indicating the face pose range into which the face pose of the identified face falls; and respectively inputting image feature characterizations derived from each of a series of regions extracted from an input image into the SVMs, so as to cause the neural network to identify whether the extracted region depicts a person's face, and whenever the extracted region is identified as depicting a person's face, to indicate the face pose range into which the face pose of the identified face falls.