Jia-song WANG, Hai-jiang SUN, Shan JIANG, et al. Auto-focusing method based on gray gradient and dark channel[J]. Chinese journal of liquid crystals and displays, 2018, 33(8): 669-675.
DOI:
Jia-song WANG, Hai-jiang SUN, Shan JIANG, et al. Auto-focusing method based on gray gradient and dark channel[J]. Chinese journal of liquid crystals and displays, 2018, 33(8): 669-675. DOI: 10.3788/YJYXS20183308.0669.
Auto-focusing method based on gray gradient and dark channel
In order to solve the problem of current focus measure function
such as low sensitivity
poor robustness and easy to enter the saturated zone
a new function based on gray gradient and dark channel is proposed. Firstly
a characteristic is analyzed and proved that a clear image has brighter and sparser dark channel compared with a defocus image. Secondly
the
L
0
norm of dark channel is selected to estimate the degree of defocus. Finally
a new focus measure function is constructed by integrating the gray gradient and the
L
0
norm of dark channel. The processing speed of single core of DSP is 9 Hz
which basically meets real-time performance in focusing experiments on various scenes such as forests
roads
drones in the sky
indoor still life
etc. Also
pseudo peak cannot be observed when the focusing process is disturbed and the function can still maintain a certain degree of steepness when the defocus is serious. A series of experiment results showed that the focus measure function proposed in this paper has good sensitivity and robustness
which can meet the real-time focusing requirement in electro-optical imaging system.
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Fast auto-focusing method based on human visual system
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Related Author
HUANG De-tian
LIU Xue-chao
ZHANG Hong-sheng
ZHAO Jing-li
Peng-fei LI
Xiao-hai HE
Lin-bo QING
Wei SHI
Related Institution
College of Engineering, Huaqiao University
Graduate University of Chinese Academy of Sciences
Key Laboratory of Optics System Advanced Manufacturing Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences
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