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Optics Express

Optics Express

  • Editor: Andrew M. Weiner
  • Vol. 22, Iss. 15 — Jul. 28, 2014
  • pp: 18668–18687

Flexible focus function consisting of convex function and image enhancement filter

Kai Wang, Yuntao Qian, Minchao Ye, and Zhijian Luo  »View Author Affiliations

Optics Express, Vol. 22, Issue 15, pp. 18668-18687 (2014)

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We propose a new focus function Λ that, like many of the existing focus functions, consists of a convex function and an image enhancement filter. Λ is rather flexible because for any convex function and image enhancement filter, it is a focus function. We proved that Λ is a focus function using a model and Jensen’s inequality. Furthermore, we generated random Λs and experimentally applied them to simulated and real blurred images, finding that 98% and 99% of the random Λs, respectively, have a maximum value at the best-focused image and most of them decrease as the defocus increases. We also applied random Λs to motion-blurred images, blurred images in different-sized windows, and blurred images with different types of noise. We found that Λ can be applied to motion blur and is robust to different-sized windows and different noise types.

© 2014 Optical Society of America

OCIS Codes
(000.3870) General : Mathematics
(110.3000) Imaging systems : Image quality assessment
(180.0180) Microscopy : Microscopy
(260.5950) Physical optics : Self-focusing

ToC Category:
Image Processing

Original Manuscript: January 2, 2014
Revised Manuscript: March 12, 2014
Manuscript Accepted: July 14, 2014
Published: July 25, 2014

Virtual Issues
Vol. 9, Iss. 9 Virtual Journal for Biomedical Optics

Kai Wang, Yuntao Qian, Minchao Ye, and Zhijian Luo, "Flexible focus function consisting of convex function and image enhancement filter," Opt. Express 22, 18668-18687 (2014)

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