Abstract:
An electronic device that can selectively enable a facial recognition unlock mechanism of the electronic device includes: a display screen, for displaying information to be viewed by a user; a camera, for capturing at least an image; a light level determining module, for determining ambient light levels; and a facial unlocking module, for comparing a captured image with a stored image and unlocking the electronic device when the captured image is determined to match the stored image. When the light level determining module determines that ambient light levels fall outside a predetermined range for performing a facial recognition function on a captured image, the display screen will inform the user via a display mechanism on the display screen.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to electronic devices which use a facial recognition technique to unlock the device, and more particularly, to electronic devices using facial recognition to unlock the device wherein the electronic device utilizes a light level determining module as a means for selectively enabling the facial recognition unlocking method or an alternative unlocking method. 
         [0003]    2. Description of the Prior Art 
         [0004]    Modern smart phones and other personal electronic devices often incorporate a facial recognition feature. This allows a user to capture their image on the electronic device&#39;s dedicated camera, match the image to a stored image in the database by the means of image rendering technology, and then unlock the device if there is an image match. 
         [0005]    When the electronic device is powered on and the camera is operative, a certain amount of time will be required for the camera to perform necessary operations such as exposure. Please note that similar steps may need to be undergone when an electronic device ‘wakes up’ from a standby state. Once the image is captured, if the image does not match a stored image (i.e. an image of the owner), the electronic device will return a negative acknowledgment and another unlock method (such as typing a password) will need to be entered. This is a built in security feature of the device. When the camera cannot capture enough detail due to under/over exposure, the facial recognition cannot be performed. In this case, even if the user is the owner of the electronic device, the electronic device will still return a negative acknowledgment and a different unlock method will need to be entered. 
         [0006]    The under/over exposure could happen for a number of reasons. The environment in which the image is captured may be too dark or too bright, such that the object in the image does not display enough detail. In these situations, it will be impossible for the camera to capture an image for which facial recognition can be performed, but the user must still wait for the camera to perform the above-mentioned exposure control, even though the electronic device will ultimately switch to another unlocking procedure. This decreases the efficiency of the device and results in an annoying and unsatisfactory user experience. 
         [0007]    Therefore, the invention aims to provide a technique for selecting an appropriate unlock method for an electronic device. 
       SUMMARY OF THE INVENTION 
       [0008]    An electronic device that can selectively enable a facial recognition unlock mechanism of the electronic device comprises: a display screen, for displaying information to be viewed by a user; a camera, for capturing at least an image; a light level determining module, for determining ambient light levels; and a facial unlocking module, for comparing a captured image with a stored image and unlocking the electronic device when the captured image is determined to match the stored image. When the light level determining module determines that ambient light levels fall outside a predetermined range for performing a facial recognition function on a captured image, the display screen will inform the user via a display mechanism on the display screen. 
         [0009]    A method for selectively enabling a facial recognition unlock mechanism of an electronic device comprises: utilizing a light level determining module to determine ambient light levels; when the light level determining module determines ambient light levels are within a predetermined range, capturing the image and using a facial unlocking module to compare the captured image with a stored image, and unlocking the electronic device when the captured image is determined to match the stored image; and when the light level determining module determines ambient light levels fall outside the predetermined range, activating a display mechanism on a display screen of the electronic device. 
         [0010]    A computer programmable medium disposed in an electronic device is also disclosed, wherein the computer programmable medium performs the steps of: detecting ambient light levels with a light sensor of the electronic device; determining whether detected ambient light levels fall within a predetermined range; and when determining the ambient light levels fall within the predetermined range, capturing an image with a camera of the electronic device, and comparing the captured image with a stored image to activate a facial unlocking module for unlocking the electronic device. 
         [0011]    These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a diagram of a conventional smart phone illustrating location of various components of the smart phone. 
           [0013]      FIG. 2  is a flowchart of an exemplary method for unlocking the smart phone illustrated in  FIG. 1  according to the present invention. 
           [0014]      FIG. 3  is a flowchart of an adjustment step illustrated in  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    Please refer to  FIG. 1 , which is a diagram of a conventional smart phone  100 . Please note that a smart phone is illustrated herein as an exemplary embodiment of the invention, but any personal electronic device which has a dedicated camera and light level determining module and employs a facial recognition procedure as a means for unlocking the electronic device falls within the scope of the invention. As illustrated in the diagram, the smart phone  100  includes a dedicated camera  102 . The smart phone also includes a display  104 , as well as a light level determining module  106 . The display  104  may comprise a touch screen input. The light level determining module  106  is for determining the amount of ambient light in a certain environment which is used as a barometer for adjusting the brightness of the display  104 . Shown in dashed lines (as this component is internal to the smart phone  100 ) is a facial unlocking module  108 , which uses facial recognition software as a basis for unlocking the smart phone  100 . Please note that the positioning of the elements on the smart phone  100  is merely one example; what is important is that both the light level determining module  106  and the dedicated camera  102  are front facing, i.e. facing the user. 
         [0016]    As mentioned in the background, when a smart phone is powered on, the dedicated camera  102  of the smart phone  100  requires a certain amount of time to perform necessary exposure control. If a level of ambient light falls outside a threshold range—for example, ambient light is too bright so that ambient light levels are greater than an upper threshold of the threshold range, or ambient light is too dark so that ambient light levels fall below a lower threshold of the threshold range—then the electronic device  100  will be unable to successfully perform facial recognition on the captured image, the facial unlocking module  108  cannot be operated, and an alternative unlocking method will need to be entered. The efficiency and user experience of the device is compromised by this process. The exemplary embodiments detailed herein therefore provide a method which can quickly determine whether or not the facial recognition can be successfully performed on a captured image. 
         [0017]    As illustrated in  FIG. 1 , the smart phone  100  includes a light level determining module  106  for determining a level of ambient light. The light level determining module  106  will be operable far earlier than the dedicated camera  102  after the smart phone  100  is powered on or woken up; the invention can therefore use the light level determining module  106  to determine whether ambient light levels fall within a range which allows facial recognition to be performed on a captured image and the facial unlocking module  108  to be operated. Please note that power-on means a state wherein the smart phone  100  is powered-up or booted-up from a shutdown state, whereas wake-up means that normal operation of the smart phone  100  resumes from a sleep or hibernate state. If the ambient light levels fall outside the range, the smart phone  100  can inform the user in some way, automatically adjust parameters of the smart phone  100  to enable the facial unlocking module  108 , or directly enter the alternative unlock method, such that the user&#39;s time is not wasted. Please note that the range of ambient light levels in which facial recognition can be performed can be determined in advance, in accordance with a specification of the facial recognition technology used by the smart phone  100 . 
         [0018]    An exemplary method is illustrated in  FIG. 2 . The steps of the method are detailed as follows: 
         [0019]    Step  200 : Power on or wake up the smart phone; 
         [0020]    Step  202 : Light level determining module is turned on; 
         [0021]    Step  204 : Enable the camera; 
         [0022]    Step  206 : Is the light level determining module ready? If yes, go to Step  208 ; if no, return to Step  206 ; 
         [0023]    Step  208 : According to the light level determining module, do the ambient light levels fall within a predetermined range? If yes, go to Step  210 ; if no, go to Step  212 ; 
         [0024]    Step  210 : Capture the image, perform facial recognition, and activate the facial unlocking module; 
         [0025]    Step  212 : Inform the user via a display mechanism that ambient light levels fall outside the predetermined range; 
         [0026]    Step  214 : Adjust at least one parameter of the smart phone. 
         [0027]    Step  216 : Can the facial unlocking module be operated after adjustment? If yes, go to Step  210 ; if no, go to Step  218 ; 
         [0028]    Step  218 : Enter an alternative unlocking method. 
         [0029]    In the flowchart, when it is determined in Step  208  that the ambient light levels fall outside the predetermined range, the smart phone  100  first informs the user via a display mechanism: for example, an error message on the screen, or a flashing light (Step  212 ). The smart phone  100  then enters an adjustment method (step  214 ) wherein it can adjust a plurality of parameters of the smart phone  100 . Please note that one, some or all of the parameters can be adjusted, and parameters can be adjusted separately (i.e. one by one), or at the same time. If it is determined that the facial unlocking module can be operated after the adjustment, the flow returns to Step  210  and the image is captured. If it is determined in Step  216  that the facial unlocking module still cannot be operated after adjustment of the parameters, the smart phone  100  will enter an alternative unlocking method (Step  218 ). Please note that certain modifications can be made to the above flowchart. For example, it is possible for the smart phone  100  to directly enter the alternative unlocking method without adjusting any parameters. Determination as to which modification is implemented can be made according to requirements. 
         [0030]    Please refer to  FIG. 3 , which details an adjustment method of Step  214 . This is a preferred embodiment of the adjustment method, wherein parameters are adjusted in turn. As detailed above, it is also possible for all parameters to be adjusted at the same time, or for the order in which parameters are adjusted to be changed. As one skilled in the art would be able to make the necessary modifications after reading the disclosure, further detail is not provided. 
         [0031]    Step  300 : Are ambient light levels above an upper threshold or below a lower threshold of the threshold range? If they are above an upper threshold, go to Step  301 ; if they are below a lower threshold, go to Step  313 ; 
         [0032]    Step  301 : Decrease the light sensitivity of the camera; 
         [0033]    Step  303 : Are ambient light levels within the threshold range? If yes, go to Step  304 ; if no, go to Step  305 ; 
         [0034]    Step  304 : Go to Step  210  in  FIG. 2 ; 
         [0035]    Step  305 : Decrease a shutter speed of the camera; 
         [0036]    Step  307 : Are ambient light levels within the threshold range? If yes, go to Step  308 ; if no, go to Step  325 ; 
         [0037]    Step  308 : Go to Step  210  in  FIG. 2 ; 
         [0038]    Step  313 : Increase the light sensitivity of the camera; 
         [0039]    Step  315 : Are ambient light levels within the threshold range? If yes, go to Step  304 ; if no, go to Step  317 ; 
         [0040]    Step  317 : Increase a shutter speed of the camera; Step  319 : Are ambient light levels within the threshold range? If yes, go to Step  308 ; if no, go to Step  321 ; 
         [0041]    Step  321 : Activate a spotlight of the electronic device; 
         [0042]    Step  323 : Are ambient light levels within the threshold range? If yes, go to Step  324 ; if no, go to Step  325 ; 
         [0043]    Step  324 : Go to Step  210  in  FIG. 2 ; 
         [0044]    Step  325 : Increase sensitivity levels of the facial unlocking module and go to Step  216  in  FIG. 2 . 
         [0045]    Initially, it is determined whether the ambient light levels are above an upper threshold or below a lower threshold of the threshold range (Step  300 ). According to the determination, light sensitivity of the camera  104  will either be lowered (Step  301 ) or increased (Step  313 ). Respective determinations (steps  303  and  315 ) are then made as to whether ambient light levels fall within the threshold or not. If they fall within the threshold, the flow will proceed to Step  304 , and then to Step  210  in  FIG. 2 , wherein the image will be captured and the facial unlocking module will be activated. 
         [0046]    If ambient light levels are still outside the threshold range, the flow proceeds, respectively, to Step  305  where shutter speed of the camera will be decreased, or to Step  317  where shutter speed of the camera will be increased. Further respective determinations (steps  307  and  319 ) are again made as to whether ambient light levels fall within the threshold or not. If they fall within the threshold, the flow will proceed to Step  308 , and then to Step  210  in  FIG. 2 , wherein the image will be captured and the facial unlocking module will be activated. 
         [0047]    If it is determined in Step  307  that ambient light levels are outside the threshold, the flow will proceed to Step  325 , where sensitivity levels of the facial unlocking module are increased. The flow then returns to Step  216  in  FIG. 2 , where it is determined whether the facial unlocking module can be operated. 
         [0048]    If it is determined in Step  319  that ambient light levels are outside the threshold, the flow will proceed to Step  321 , wherein a spotlight of the electronic device will be activated. In Step  323  it is determined whether ambient light levels fall within the threshold or not. If they fall within the threshold, the flow will proceed to Step  324 , and then to Step  210  in  FIG. 2 , wherein the image will be captured and the facial unlocking module will be activated. If it is determined in Step  323  that ambient light levels are outside the threshold, the flow will proceed to Step  325 , where sensitivity levels of the facial unlocking module are increased. The flow then returns to Step  216  in  FIG. 2 , where it is determined whether the facial unlocking module can be activated. 
         [0049]    It is also possible to reverse the order of Step  204 , Step  206  and Step  208 , such that the camera  102  is only turned on when the light sensor  106  verifies ambient light levels fall outside the predetermined range for performing facial recognition. The order shown in  FIG. 2  is the preferred method, however, as the camera  102  will require some time before it becomes operable. It is also possible that the light level determining module  106  which is used is the light sensor of the dedicated camera  102 . 
         [0050]    As the present invention can quickly determine whether or not ambient light levels fall within a particular required range for performing facial recognition so that a facial unlocking module cannot be operated, an electronic device can quickly determine that an alternative unlock method needs to be entered. If the ambient light levels fall outside the particular range, the electronic device can also adjust the light sensitivity and/or the shutter speed of the camera, activate a spotlight for increasing the ambient light in the same environment, increase the sensitivity of the facial unlocking module such that the image can still be recognized and the facial unlocking module can be activated, or select an alternative unlock method. If the electronic device directly enters the alternative unlock method, the user can still quickly unlock and operate the electronic device. Therefore, both efficiency and user satisfaction are increased. 
         [0051]    Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.