Image Restoration Preprocessing for Low Light Auto-Focusing in Digital Cameras

Author

Gamadia, Mark ; Kehtarnavaz, Nasser

Author_Institution

Univ. of Texas at Dallas, Richardson

fYear

2007

fDate

20-23 June 2007

Firstpage

1

Lastpage

5

Abstract

The performance of passive auto-focus (AF) systems suffers when operating under low-lighting conditions due to the flatness of the sharpness function. In this paper, an adaptive noise reduction method prior to AF sharpness filter is introduced for the purpose of elevating the suppressed peak in the sharpness function . Experimental results show that the use of adaptive noise reduction preprocessing enables focusing at lower lux levels as compared to non-adaptive noise reduction preprocessing.

Keywords

cameras; image restoration; optical filters; optical focusing; adaptive noise reduction; auto-focus sharpness filter; digital cameras; image restoration preprocessing; low light auto-focusing; passive auto-focus systems; Adaptive filters; Boosting; Digital cameras; Fluctuations; Focusing; Image restoration; LED lamps; Noise reduction; Nonlinear filters; Signal to noise ratio; Low-light auto-focus; adaptive noise reduction preprocessing; auto-focus sharpness function; cell-phone cameras; digital still cameras;

fLanguage

English

Publisher

ieee

Conference_Titel

Consumer Electronics, 2007. ISCE 2007. IEEE International Symposium on

Conference_Location

Irving, TX

Print_ISBN

978-1-4244-1109-2

Electronic_ISBN

978-1-4244-1110-8

Type

conf

DOI

10.1109/ISCE.2007.4382161

Filename

4382161