DocumentCode :
1320513
Title :
A new auto-focus sharpness function for digital and smart-phone cameras
Author :
Yousefi, Siamak ; Rahman, Mosaddequr ; Kehtarnavaz, Nasser
Author_Institution :
Univ. of Texas at Dallas, Dallas, TX, USA
Volume :
57
Issue :
3
fYear :
2011
fDate :
8/1/2011 12:00:00 AM
Firstpage :
1003
Lastpage :
1009
Abstract :
Passive auto-focusing is a key feature in digital cameras and smart-phones which uses the image sharpness information to capture focused images without any user intervention. This paper introduces a new sharpness function for achieving passive auto-focusing in digital cameras and smart-phones. It is shown that this sharpness function produces a peak when the image is in-focus and drops when the image goes out-of-focus and the amount of drop is proportional to the degree of defocus. A comparison is made between this introduced sharpness function and the commonly used sharpness functions in terms of focusing accuracy and focusing speed. The results obtained indicate that the introduced sharpness function possesses a comparable accuracy while it achieves faster focusing.
Keywords :
cameras; mobile handsets; optical focusing; degree of defocus; digital smart-phone camera; image sharpness; passive autofocus sharpness function; Density functional theory; Digital cameras; Discrete cosine transforms; Entropy; Focusing; Joints; Kernel; Passive auto-focus; digitalcameras; sharpness function; smart-phone cameras;
fLanguage :
English
Journal_Title :
Consumer Electronics, IEEE Transactions on
Publisher :
ieee
ISSN :
0098-3063
Type :
jour
DOI :
10.1109/TCE.2011.6018848
Filename :
6018848
Link To Document :
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