Automatic focusing system in low-illumination setting and method using the same
AssigneeAltek Corporation
InventorsPeng-Wei Lin, Li-Wen Kuo
Life of this patent
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Abstract
An automatic focusing system in a low-illumination setting and a method using the same are disclosed. Through a selection of the memory bits and a tone adjustment, an automatic focusing could be precisely achieved. According to one embodiment, a lens module and an image sensor are firstly used for generating the digital image signals. Next, a gain adjustment unit is introduced to adjusting the gain of the signals, so as to reduce the noises. A memory bit retrieving unit is further used to retrieve the data from a plurality of memory bits. Next, a tone adjusting process is performed to raise the signals' contrast.
Claims17
An automatic focusing system in a low-illumination setting, comprising:
- a lens module for taking an image;
- an image sensor connected with the lens module for converting the taken image into digital image signals;
- a gain adjustment unit connected to the image sensor for adjusting a gain of the digital image signals in order to reduce a noise associated with the digital image signals;
- a memory bits retrieving unit connected with the gain adjustment unit for retrieving data in memory bits of the digital image signals after the noise associated with the digital image signals has been reduced;
- a tone adjustment unit connected with the memory bits retrieving unit for performing a tone adjustment for the digital image signals, thereby increasing a contrast of the digital image signals;
- a focused image generating unit connected with the tone adjustment unit for receiving the digital image signals, and converting the digital image signals into a focused image;
- and
- a focusing unit connected to the focused image generating unit and the lens module, wherein the focusing unit firstly calculates a definition of the focused image, and automatically adjusts the lens module for further photographing according to a focus associated with the definition.
A method for automatic focusing in a low-illumination setting, comprising:
- (a) capturing an image by a lens module and converting the image into a corresponding digital image signal through an image sensor;
- (b) determining an illumination of the image, and when the illumination of the image is indicative of the image is captured in the low-illumination setting, further comprising:
- (i) adjusting a gain of the image sensor for reducing a noise associated with the digital image signal;
- (ii) selectively retrieving data in a plurality of memory bits of the digital image signal;
- (iii) adjusting tone of the digital image signal for raising a contrast of the digital image signal;
- and
- (c) enabling an automatic focusing for the lens module.
Dependencies are inferred from the claim text.