Method and apparatus for determining poses

Abstract

A method and apparatus are disclosed for determining a direction in which a subject's head is facing. The present invention has particular relevance to monitoring driver conditions in automobiles. By monitoring head positions and motions, the system can estimate driver awareness. Signals or alarms can be activated if the driver does not appear to be aware of driving conditions. The present invention provides a rapid, low cost device for determining pose position, which would be useful in automobiles. A large number of images of various subjects in different poses are stored a memory. The poses are then organized according to tree-structured vector quantization to allow comparison with a sample image of an actual driver. The tree structure is traversed to find a leaf node constituting one of the stored images which is closest to the sample image. The pose of the closest image is outputted as the pose of the sample image. Cropping can be done automatically by including, within the stored images, extra examples which are offset from center. If the closest pose is one that is offset, the cropping window for subsequent sample images is appropriately adjusted in order to maintain the head of the subject close to the center of the cropping window.