Title :
The application of discrete cosine transform (DCT) combined with the nonlinear regression routine on optical auto-focusing
Author :
Lee, Meng-En ; Chen, Chien-Feng ; Lin, Tsung-Nan ; Chen, Chun-Nan
Author_Institution :
Dept. of Phys., Nat. Kaohsiung Normal Univ., Kaohsiung
Abstract :
This paper presents a fast and accurate real-time optical auto-focusing system, which utilizes a frequency component of the discrete cosine transform (DCT) as the focus measure. Besides, a nonlinear regression routine is combined in the algorithm to quickly move a rotational stepper motor to the best focus. The concise and effective algorithm can be applied to digital cameras, microscopes and optical inspection instruments.
Keywords :
discrete cosine transforms; optical self-focusing; regression analysis; stepping motors; DCT; digital cameras; discrete cosine transform; microscopes; nonlinear regression routine; optical inspection instruments; real-time optical autofocusing system; rotational stepper motor; Digital cameras; Discrete cosine transforms; Frequency measurement; Inspection; Instruments; Nonlinear optical devices; Nonlinear optics; Optical devices; Optical microscopy; Real time systems;
Conference_Titel :
Consumer Electronics, 2009. ICCE '09. Digest of Technical Papers International Conference on
Conference_Location :
Las Vegas, NV
Print_ISBN :
978-1-4244-4701-5
Electronic_ISBN :
978-1-4244-2559-4
DOI :
10.1109/ICCE.2009.5012369
