1. Technical Field
Embodiments of the present disclosure relate to video capture, and more particularly to an electronic device and light control method thereof.
2. Description of Related Art
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.
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.
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.
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.
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.
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.
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.
In block S201, the capture module 110 samples an image captured by the image capture device 13, periodically or on demand In block S202, the analysis module 112 assesses brightness of the sampled image. If the sampled image is too dark, block S203 is implemented. If the sampled image is too bright, block S207 is implemented. In block S203, the feedback module 114 sends the enhancement signal to the light control system 12. In block S204, 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 S206 is implemented. Otherwise, block S205 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 S206, 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.
In block S207, the feedback module 114 sends the abatement signal to the light control system 12. In block S208, the light abatement module 122 determines whether the supplementary lighting device 14 is on. If the supplementary lighting device 14 is on, block S209 is implemented. Otherwise, if the supplementary lighting device 14 is off, block S210 is implemented. In block S209, 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 S210, 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.
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.
Number | Date | Country | Kind |
---|---|---|---|
200910312794.4 | Dec 2009 | CN | national |