Title :
Practical issues in pixel-based autofocusing for machine vision
Author :
Chern, Nathaniel Ng Kuang ; Neow, Po Aun ; Ang, Marcelo H., Jr.
Author_Institution :
Dept. of Mech. Eng., Nat. Univ. of Singapore, Singapore
Abstract :
Different autofocusing methods exist for many cameras today. While not ignoring commercially available methods requiring specialized hardware, this paper focuses mainly on pixel based autofocusing algorithms as applied to CCD camera systems. Different measures of image sharpness are compared. For each of these, different algorithms for searching the best lens setting are assessed in terms of performance as well as their applicability to various situations. In addition, several other factors potentially affecting camera focusing are also discussed. Based on the information obtained, this research attempts to formulate a robust autofocusing algorithm.
Keywords :
CCD image sensors; computer vision; optical self-focusing; CCD camera systems; image sharpness measures; lens setting; machine vision; pixel-based autofocusing; robust autofocusing algorithm; Cameras; Charge coupled devices; Charge-coupled image sensors; Focusing; Hardware; Layout; Lenses; Machine intelligence; Machine vision; Manufacturing systems;
Conference_Titel :
Robotics and Automation, 2001. Proceedings 2001 ICRA. IEEE International Conference on
Print_ISBN :
0-7803-6576-3
DOI :
10.1109/ROBOT.2001.933045
