Abstract:
An electronic device automatically adjusts luminance of a monitor device, such as an image capture device. The electronic device analyzes captured images and determines brightness thereof. If the luminance of the captured images are too dark, the electronic device widens an aperture of the monitor device or turns up a supplementary lighting device. If the luminance is too high, the electronic device narrows the aperture of the monitor device or decreases output of the supplementary lighting device.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    Embodiments of the present disclosure relate to video capture, and more particularly to an electronic device and light control method thereof. 
         [0003]    2. Description of Related Art 
         [0004]    Maintaining contrast and clarity is critical during video capture, particularly for automatic surveillance systems. Currently, many electronic devices used in such applications, such as, for example, surveillance systems, provide basic light control functions. However, these functions are often rudimentary, often involving light sensors to feed back existing environmental luminance. The cost of hardware required to implement sensor-based light control function in such devices, however, is high. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a block diagram of one embodiment of an electronic device utilizing a light control system. 
           [0006]      FIG. 2  is a flowchart illustrating one embodiment of a method for light control of an electronic device. 
       
    
    
     DETAILED DESCRIPTION 
       [0007]    The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one. 
         [0008]    In general, the word “module” as used herein, refers to logic embodied in hardware or firmware, or to a collection of software instructions, written in a programming language, such as, for example, Java, C, or assembly. One or more software instructions in the module may be integrated in firmware, such as an EPROM. It will be appreciated that module may comprise connected logic units, such as gates and flip-flops, and may comprise programmable units, such as programmable gate arrays or processors. The units described herein may be implemented as software and/or hardware unit and may be stored in any type of computer-readable medium or other computer storage device. 
         [0009]      FIG. 1  is a block diagram of an electronic device  10  comprising a luminance system  11  and a light control system  12 . The luminance system  11  samples images captured by an image capture device  13 . The image capture device  13  is electronically connected with the electronic device  10 . In the embodiment, the image capture device  13  can be a camera or a video recorder. The luminance system  11  measures luminance of the sampled images, and provides the result to the light control system  12 . The light control system  12  adjusts an aperture of the image capture device  13 , and a supplementary lighting device  14  accordingly. Depending on the embodiment, the electronic device  10  can be a personal computer or notebook, for example. The supplementary lighting device  14  can be an LED light, fluorescent, or other light types. 
         [0010]    In the embodiment, the luminance system  11  comprises programs including a capture module  110 , an analysis module  112 , and a feedback module  114 . The light control system  12  comprises a light enhancement module  120  and a light abatement module  122 . One or more computerized codes of the modules  110 - 122  are stored in a memory system  102  and executed by one or more processors  101  of the electronic device  10 . 
         [0011]    In the embodiment, the capture module  110  samples an image captured by the image capture device  13 , periodically or on demand The analysis module  112 , computes an average luminance for the sampled image, and compares the average luminance with a predetermined threshold. 
         [0012]    In the embodiment, if the average luminance exceeds the predetermined threshold by a predetermined margin, the feedback module  114  sends an electronic signal to the light control system  12  so as to increase the luminance (hereinafter “the enhancement signal”). When the light control system  12  receives the enhancement signal, the light enhancement module  120  widens the aperture of the image capture device  13  to admit more light, and increases the output of the supplementary lighting device  14  if the aperture has reached a maximum value, until the average luminance is within the predetermined margin. 
         [0013]    In the embodiment, if the average luminance is below the predetermined threshold by a predetermined margin, the feedback module  114  sends an electronic signal to the light control system  12  so as to decrease the luminance (hereinafter “the abatement signal”). When the light control system  12  receives the abatement signal, the light abatement module  122  decreases output of the supplementary lighting device  14 , and narrows the aperture of the image capture device  13  if the supplementary lighting device  14  is off, until the average luminance is within the predetermined margin. 
         [0014]      FIG. 2  is a flowchart illustrating one embodiment of a method for light control of the electronic device  10 . Additional blocks may be added to the method, others removed, and the ordering of the blocks may be changed. 
         [0015]    In block S 201 , the capture module  110  samples an image captured by the image capture device  13 , periodically or on demand In block S 202 , the analysis module  112  assesses brightness of the sampled image. If the sampled image is too dark, block S 203  is implemented. If the sampled image is too bright, block S 207  is implemented. In block S 203 , the feedback module  114  sends the enhancement signal to the light control system  12 . In block S 204 , the light enhancement module  120  determines whether the aperture of the image capture device  13  has reached a maximum value. If the aperture of the image capture device  13  has reached a maximum value, block S 206  is implemented. Otherwise, block S 205  is implemented, in which light enhancement module  120  widens the aperture of the image capture device  13  until the average luminance of the sampled image is within the predetermined margin or the aperture of the image capture device  13  has reached a maximum. In block S 206 , the light enhancement module  120  increases output of the supplementary lighting device  14  until the average luminance of the sampled image is within the predetermined margin. 
         [0016]    In block S 207 , the feedback module  114  sends the abatement signal to the light control system  12 . In block S 208 , the light abatement module  122  determines whether the supplementary lighting device  14  is on. If the supplementary lighting device  14  is on, block S 209  is implemented. Otherwise, if the supplementary lighting device  14  is off, block S 210  is implemented. In block S 209 , the light abatement module  122  decreases output of the supplementary lighting device  14  until the average luminance is within the predetermined margin or the supplementary lighting device  14  is off. In block S 210 , the light abatement module  122  narrows the aperture of the image capture device  13  if the supplementary lighting device  14  is off until the average luminance is within the predetermined margin. 
         [0017]    Although certain inventive embodiments of the present disclosure have been specifically described, the present disclosure is not to be construed as being limited thereto. Various changes or modifications may be made to the present disclosure without departing from the scope and spirit of the present disclosure.