Method and apparatus for tracking locations using webcams

Abstract

Disclosed herein are a location tracking apparatus and method. The location tracking apparatus includes a head tracking unit, and a pointer tracking unit. The head tracking unit extracts a location, 3DOF and orientation of a head of a user by capturing the user from a screen on which a game is displayed using a first webcam and tracks the user's gaze based on the results of the extraction. The pointer tracking unit tracks a point indicated by a laser pointer projected onto the screen by capturing the screen using a second webcam, and designates the tracked point as cross hairs corresponding to a target to be shot at. The head tracking unit and the pointer tracking unit tracks the user's gaze and the point simultaneously.

1 . A method in which an apparatus operating in conjunction with a First-Person Shooter (FPS) game tracks a user performing the game and a location of a laser pointer held by the user, the method comprising:
 extracting a location, 3-Degrees Of Freedom (3DOF) and orientation of a head of the user by capturing the user from a screen on which the game is displayed using a first webcam, and tracking the user's gaze based on results of the extraction; and   capturing the screen using a second webcam, and tracking a point, indicated by the laser pointer and projected onto the screen, based on the results of the capturing.   
     
     
         2 . The method as set forth in  claim 1 , wherein the user's gaze and the point of the laser pointer are tracked simultaneously. 
     
     
         3 . The method as set forth in  claim 1 , wherein the tracking the user's gaze comprises:
 extracting at least one feature point based on the results of the capturing of the head of the user, performed by the first webcam disposed above the screen;   constructing a statistical model by applying the feature point to a machine learning algorithm; and   extracting the location, 3DOF, and orientation of the head of the user based on the statistical model.   
     
     
         4 . The method as set forth in  claim 3 , wherein the feature point comprises at least one of a face color, an eye, a nose, and a mouth of the user. 
     
     
         5 . The method as set forth in  claim 1 , wherein the tracking the point indicated by the laser pointer comprises:
 performing calibration on a frame including the point;   measuring a pixel intensity of the calibrated frame; and   comparing the pixel intensity and a critical value, and making a determination of whether to track the point depending on results of the comparison.   
     
     
         6 . The method as set forth in  claim 5 , further comprising, if the pixel intensity is equal to or higher than the critical value:
 grouping pixels whose intensities are equal to or higher than the critical value;   performing Kalman filtering on the grouped pixels; and   smoothing results of the Kalman filtering and tracking the point.   
     
     
         7 . The method as set forth in  claim 5 , further comprising, if the pixel intensity is smaller than the critical value, measuring the pixel intensity of the calibrated frame again. 
     
     
         8 . The method as set forth in  claim 1 , wherein in the tracking the point indicated by the laser pointer, the tracked point is designated as cross hairs corresponding to a target in the game to be shot at. 
     
     
         9 . A location tracking apparatus, comprising:
 a head tracking unit for extracting a location, 3DOF and orientation of a head of a user by capturing the user from a screen on which a game is displayed using a first webcam and tracking the user's gaze based on results of the extraction; and   a pointer tracking unit for tracking a point indicated by a laser pointer projected onto the screen by capturing the screen using a second webcam, and designating the tracked point as cross hairs corresponding to a target to be shot at;   wherein the head tracking unit and the pointer tracking unit track the user's gaze and the point simultaneously.   
     
     
         10 . The location tracking apparatus as set forth in  claim 9 , wherein the head tracking unit constructs a statistical model based on the results of the capturing performed by the first webcam disposed above the screen, and extracts the location, 3DOF, and orientation of the head of the user by recognizing the results of capturing the head of the user based on the statistical model. 
     
     
         11 . The location tracking apparatus as set forth in  claim 9 , wherein the pointer tracking unit performs calibration on a frame including the point, measures a pixel intensity of the calibrated frame, compares the pixel intensity with a critical value, and determines whether to track the point depending on results of the comparison. 
     
     
         12 . The location tracking apparatus as set forth in  claim 11 , wherein if the pixel intensity is equal to or higher than the critical value, the pointer tracking unit groups pixels whose intensities are equal to or greater than the critical value, performs Kalman filtering on the grouped pixels, smoothes the Kalman filtered result, and tracks the point. 
     
     
         13 . The location tracking apparatus as set forth in  claim 11 , wherein if the pixel intensity is smaller than the critical value, the pointer tracking unit measures the pixel intensity of the calibrated frame again.