Patent Publication Number: US-2004042643-A1

Title: Instant face recognition system

Description:
FIELD OF THE INVENTION  
       [0001] The present invention relates to a face recognition system and particularly to an instant face recognition system with adjustable picture-taking direction.  
       BACKGROUND OF THE INVENTION  
       [0002] With increasingly sophisticated development of information technology in recent years, information security has become more important than ever. In order to better protect information security, to restrict non relevant people from accessing information is essential and necessary. Identification recognition system is one of the mostly used methods to separate eligible or authorized people from the non eligible people to access the protected information.  
       [0003] At present, the commonly used identification recognition system is password. People who are authorized to access information have a password which allows the password owner to access selected information within the authorized scope. However passwords are easy to be compromised or stolen. To remedy this problem, some new and more sophisticated identification recognition systems have been developed, such as recognition systems for fingerprint, voice, iris, or face. Among them, the system that captures and recognizes people&#39;s features such as eyes, noses, mouths, face profiles is more popular. Because at an user end, it can function by employing only one video camera coupled with the matching software. In terms of equipment costs and user-friendliness, it provides more advantages than those for recognizing fingerprints, voices and irises.  
       [0004] Among conventional instant face recognition systems, ROC patent application No. 89115192 discloses a face recognition system based on people&#39;s face features. Its functional block diagram is shown in FIG. 1. As shown in FIG. 1, the face recognition system  2  consists of a video camera  4  and a computer  6 . The computer  6  includes a video module  8 , a face detection module  10 , a facial features detection module  12 , a face recognition module  14 , a reference database  16  and an input/output module  18 . The video camera  4  usually is installed on the computer  6  or in the vicinity of the computer  6  for capturing users&#39; head images. The computer  6  is for processing images and database management.  
       [0005] The video module  8  receives users&#39; heads images captured by the video camera  4 . The reference database  16  stores a plurality of facial images for reference and comparison. The stored facial images are transferred in advance to Invariant space and are stored in the reference database  16  in Invariant faces formats. The face detection module  10  is coupled with the video module  8  for detecting facial areas in the head images. The facial features detection module  12  detects a plurality of facial features from the facial areas and transfers the facial features to the Invariant space to become an invariant vector.  
       [0006] The face recognition module  14  calculates the invariant vector of the facial features and similarity of the Invariant faces stored in the reference database  16 , and based on the similarity to provide a confidence index. The input/output module  18  couples with a plurality of input or output devices, such as mouse, display devices, electric door locks, card readers, keyboards, sensors, and the likes to allow users to activate face recognition processes (such as sliding a card) and output results of the face recognition processes (such as open an electric door lock).  
       [0007] However the face recognition system and other known conventional instant face recognition systems have a common problem, i.e. the lens of the video camera is still and cannot be turned. Users have to turn their faces in front of the lens to have their face images taken by the video camera. As users&#39; physical heights are different widely, for those users who have unusual physical heights such as very tall or very short, it could be very awkward and trying, such as standing on the toes or bending downwards, to put their faces in front of the still video camera lens.  
       [0008] It is obvious that to develop a face recognition system to overcome aforesaid problems is very important.  
       SUMMARY OF THE INVENTION  
       [0009] Therefore the object of the invention is to provide an instant face recognition system with a video camera lens capable of adjusting picture-taking direction for rapidly and accurately pointing to users located in various directions to process face recognition.  
       [0010] The face recognition system of the invention processes face recognition based on user&#39;s face. The system includes an image capturing module for capturing images, a picture-taking direction control module coupling with the image capturing module for controlling picture-taking direction of the image capturing module to take user&#39;s head images, and a facial image processing module coupling with the image capturing module to detect user&#39;s facial features from user&#39;s head images captured by the image capturing module and compare the facial features to process recognition.  
       [0011] The image capturing module includes a video camera and a video driver to obtain RGB (Red, Green, Blue) original data of the head images. The picture-taking direction control module includes a motor coupling with the image capturing module to drive the picture-taking direction of the image capturing module, and a picture-taking direction adjustment module coupling with the motor for adjusting turning angle of the motor.  
       [0012] The facial image processing module includes at least: a storage module for storing a plurality of facial images for reference and comparing use, the stored facial images are transferred to Invariant spaces in advance and are stored in the storage module in formats of Invariant faces; a face detection module coupling with the image capturing module for detecting face image locations from the head images; a facial features detection module coupling with the face detection module for detecting a plurality of facial features from the face images and transferring every facial feature to Invariant spaces to become an Invariant vector; and a face recognition module for calculating the Invariant vectors of the face features and similarity degree of the Invariant faces stored in the storage module, and based on the similarity providing a confidence index.  
       [0013] The storage module includes an Invariant face database and an Invariant facial features database. The processes of calculating the Invariant vectors of the face features and similarity degree of the Invariant faces stored in the storage module are accomplished by employing Invariant Hadamard Transform algorithm or Invariant Critical Element Analysis. The face detection module is driven by an input module which includes mouse, electric door locks, card readers, sensors or a keyboards coupling with the face recognition system.  
       [0014] The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0015]FIG. 1 is a functional block diagram of a conventional face recognition system.  
     [0016]FIG. 2 is a functional block diagram of an embodiment of the face recognition system of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
     [0017] In view of conventional face recognition systems that employ a still video camera lens to capture face images and result in users have to face directly in front of the lens of the video camera for picture-taking, and could put users in awkward situations, such as standing on the toes or bending downwards, in the event of users&#39; physical sizes do not match the elevation of the video camera lens, the invention aims at resolving the foregoing disadvantage by providing an instant face recognition system with a video camera lens that is capable of adjusting picture-taking directions and can rapidly and accurately turning to various directions to capture users&#39; face images to process face recognition.  
     [0018] Refer to FIG. 2 for an embodiment of the invention. The face recognition system  22  of the invention includes at least: an image capturing module  24  for capturing images, a picture-taking direction control module  25  coupling with the image capturing module  24  for controlling picture-taking direction of the image capturing module  24  to take user&#39;s head images, a facial image processing module  26  coupling with the image capturing module  24  to detect user&#39;s facial features from user&#39;s head images captured by the image capturing module  24  and compare the facial features to process recognition.  
     [0019] The image capturing module  24  includes a video camera and a video driver to obtain RGB (Red, Green, Blue) original data of the head images. The picture-taking direction control module  25  includes a motor  25   b  (such as a step motor) coupling with the image capturing module  24  to drive the image capturing module  24  moving to desired picture-taking directions, and a picture-taking direction adjustment module  25   a  coupling with the motor  25   b  for adjusting turning angle of the motor  25   b.    
     [0020] The facial image processing module  26  may be a computer including functions as those disclosed in ROC Patent Application No. 89115192. Specifically, the facial image processing module  26  may include: a video module  28 , a face detection module  30 , a facial features detection module  32 , a face recognition module  34 , a storage module  36  and an input/output module  38 . The video module  28  couples with the image capturing module  24  for receiving users&#39; head images captured by the image capturing module  24 . The storage module  36  includes an Invariant face database and an Invariant facial features database for storing a plurality of facial images for reference and comparing use. In other words, the facial images stored in the storage module  36  are transferred to mathematical Invariant spaces in advance and are stored in the storage module  36  in formats of Invariant faces.  
     [0021] The face detection module  30  couples with the video module  28  for detecting face areas from the head images. The detection processes include: first, examine all possible objects of face areas in the head images; then based on Invariant Hadamard Transform algorithm or Invariant Critical Element Analysis to calculate the most possible objects of the face areas.  
     [0022] The facial features detection module  32  couples with the face detection module  30  and the storage module  36  for detecting a plurality of facial features from the face areas, and transferring every facial feature to Invariant spaces to become an Invariant vector. The facial features include eyes, noses, mouths, wrinkles on eye corners, and the likes. The face recognition module  34  couples with the facial features detection module  32  and the storage module  36  for comparing the detected facial features with the facial features stored in the Invariant face database and the Invariant facial features database, and calculating the Invariant vectors of the face features and similarity degree of the Invariant faces stored in the storage module  36 , and based on the similarity provides a confidence index.  
     [0023] The input/output module  38  couples with a plurality of input or output devices, such as mouse devices, display devices, electric door locks, card readers, keyboards and the likes to allow users to activate the face recognition processes (such as sliding a card) or output face recognition results (such as opening an electric door lock).  
     [0024] Of course, before implementing the face recognition system of the invention, a training procedure is required. Reference for the training procedure can be found in ROC Patent Application No. 89115192. As it forms no part of the invention, details are omitted here. Operation of the face recognition of the invention, in addition to employing the picture-taking direction control module  25  to control picture-taking direction of the image capturing module  24  for capturing users&#39; head images, processing procedures of the facial image processing module  26  after the image capturing module  24  has captured users&#39; head images also can be found in ROC Patent Application No. 89115192.  
     [0025] While the preferred embodiment of the invention has been set forth for the purpose of disclosure, modifications of the disclosed embodiment of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.