System and method for detecting an occupant and head pose using stereo detectors

A method for training stereo detectors for use in real-time head pose detection comprises the steps of:

• collecting pairs of images of an individual's head, each pair of images depicting a different head pose;
• collecting pairs of images of additional individuals' heads, each pair of images for each additional individual depicting different head poses;
• identifying and labeling a set of components for each pair of images;
• indexing data pertaining to each identified component;
• storing the indexed data in a database;
• defining a plurality of features that are associated with each identified component in stereo image pairs;
• and
• for each component, determining a subset of features that best discriminate positive component examples.
• for each component, determining a classification function which generates a classification score from the set of discriminative features.

A method for testing a pair of images to identify stereo components in the images comprising the steps of:

• using a window of a predetermined size to sample a portion of a first image;
• calculating a subset of discriminative features and a classification score for the window;
• if the classification score is above a predetermined threshold, determining presence of a component in the window;
• and
• sliding the window to an adjacent position and calculating the classification score for the window in the adjacent position.

A method for detecting an occupant of a vehicle comprising the steps of:

• a). capturing a pair of images of a person from a pair of stereo cameras;
• b). applying a head detector and shoulder detector to identify head and shoulder from one image;
• c). locating positions with high classification scores in a first image of the pair of images;
• d). if the classification score at a location in the first image is above a predetermined threshold, locating a corresponding region in a second image of the pair of images;
• e). determining if a head and shoulder component is detected in the second image;
• f). if a head and shoulder component is detected at corresponding positions in stereo image pair, using the head and shoulder component as an initial matching point for stereo matching;
• g). performing stereo matching on the head and shoulder component to obtain correspondence information;
• h). feeding back the correspondence information to a detection module;
• i). using the correspondence information to refine the detection region in the pair of images and to generate new detection information;
• j). repeating steps e), f), g), h) and until convergence between the correspondence information and detection information is obtained;
• and
• k). determining if an occupant is present based on the detection information.

A system for detecting head pose of an individual comprises:

• a pair of camera for capturing images of a person, the pair of cameras being situated in a known position relative to one another;
• a processor associated with the pair of cameras, the processor performing the following steps:
• i). simultaneously scanning the images captured by the pair of cameras to locate at least one component in the images;
• ii). computing three dimensional (3D) locations for each of the at least one components;
• and
• iii). estimating head pose using the 3D locations.

A database system for use in real-time head pose detection comprises:

• means for receiving pairs of images of an individual's head, each pair of images depicting a different head pose;
• means for receiving pairs of images of additional individuals' heads, each pair of images for each additional individual depicting different head poses;
• means for identifying a set of components for each pair of images;
• means for indexing data pertaining to each identified component;
• means for storing the indexed data in a database;
• means for defining a plurality of features that are associated with each identified component;
• and
• means for determining a subset of features that best discriminate positive component examples for each component.