By Topic

Modified fast climbing search auto-focus algorithm with adaptive step size searching technique for digital camera

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

3 Author(s)
Jie He ; Microelectron. Dept., Fudan Univ., Shanghai, China ; Rongzhen Zhou ; Zhiliang Hong

A practical real-time auto-focus algorithm for a digital camera is presented, and it improves the reliability and speed of the auto-focus process, especially suitable for a mega-pixel high definition camera. The proposed algorithm adopts threshold gradient and edge point count technique besides focus value function, instead of the traditional two-stage climbing search algorithm that uses the focus value function only. Additionally, a relative difference ratio circuit is also proposed, which can implement adaptive step size searching to increase the searching speed. By adopting the modified algorithm on the prototype of our mega-pixel digital camera, the real-time auto-focus function is verified. The proposed algorithm is implemented in a test camera chip that has been manufactured in 0.25μm CMOS digital process.

Published in:

IEEE Transactions on Consumer Electronics  (Volume:49 ,  Issue: 2 )