Navigation Links
Researchers develop optimal algorithm for determining focus error in eyes and cameras
Date:9/26/2011

University of Texas at Austin researchers have discovered how to extract and use information in an individual image to determine how far objects are from the focus distance, a feat only accomplished by human and animal visual systems until now.

Like a camera, the human eye has an auto-focusing system, but human auto-focusing rarely makes mistakes. And unlike a camera, humans do not require trial and error to focus an object.

Johannes Burge, a postdoctoral fellow in the College of Liberal Arts' Center for Perceptual Systems and co-author of the study, says it is significant that a statistical algorithm can now determine focus error, which indicates how much a lens needs to be refocused to make the image sharp, from a single image without trial and error.

"Our research on defocus estimation could deepen our understanding of human depth perception," Burge says. "Our results could also improve auto-focusing in digital cameras. We used basic optical modeling and well-understood statistics to show that there is information lurking in images that cameras have yet to tap."

The researchers' algorithm can be applied to any blurry image to determine focus error. An estimate of focus error also makes it possible to determine how far objects are from the focus distance.

In the human eye, inevitable defects in the lens, such as astigmatism, can help the visual system (via the retina and brain) compute focus error; the defects enrich the pattern of "defocus blur," the blur that is caused when a lens is focused at the wrong distance. Humans use defocus blur to both estimate depth and refocus their eyes. Many small animals use defocus as their primary depth cue.

"We are now one step closer to understanding how these feats are accomplished," says Wilson Geisler, director of the Center for Perceptual Systems and coauthor of the study. "The pattern of blur introduced by focus errors, along with the statistical regularities of natural images, makes this possible."

Burge and Geisler considered what happens to images as focus error increases: an increasing amount of detail is lost with larger errors. Then, they noted that even though the content of images varies considerably (e.g. faces, mountains, flowers), the pattern and amount of detail in images is remarkably constant. This constancy makes it possible to determine the amount of defocus and, in turn, to re-focus appropriately.


'/>"/>

Contact: Johannes Burge
jburge@mail.cps.utexas.edu
510-604-9515
University of Texas at Austin
Source:Eurekalert

Related biology news :

1. Researchers at Cruces Hospital describe new syndrome of slight family intellectual disability
2. UCLA researchers develop system that finds prostate cancer spread earlier than conventional imaging
3. Joslin researchers identify pathways leading to activation of good fat
4. Kansas researchers find enriched infant formulas benefit brain and heart
5. Researchers sequence dark matter of life
6. Researchers discover a switch that controls stem cell pluripotency
7. MU researchers unveil new method for detecting lung cancer in Nature article
8. Notre Dame researchers demonstrate antibiotic sensing event central to MSRA antibiotic resistance
9. Researchers uncover a potential new benefit of pure maple syrup on liver health
10. EPA grants help Wayne State researchers stave off Great Lakes environmental invaders
11. UTHealth, BCM researchers find common gene variant associated with aortic dissection
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/28/2016)... Synaptics (NASDAQ: SYNA ), a leading developer of ... ended December 31, 2015. --> ... increased 2 percent compared to the comparable quarter last year to ... was $35.0 million, or $0.93 per diluted share. ... first quarter of fiscal 2016 grew 9 percent over the prior ...
(Date:1/25/2016)... Software, the world-leading supplier of image data management solutions ... data management solution OMERO Plus for the newly established ... Photo - http://photos.prnewswire.com/prnh/20160125/325328LOGO ... analysis measures the characteristics and behavior of cells, tissues ... as health and disease, the presence or absence of ...
(Date:1/21/2016)... 21, 2016 --> ... market research report "Emotion Detection and Recognition Market by Technology ... (Facial Expression, Voice Recognition and Others), Services, Application ... to 2020", published by MarketsandMarkets, the global Emotion ... USD 22.65 Billion by 2020, at a CAGR ...
Breaking Biology News(10 mins):
(Date:2/10/2016)... ... February 10, 2016 , ... Global Stem Cells ... with Singapore-based Global Stem Cells Network (GSCN) and its affiliate Global Medical ... the latest adipose and bone marrow therapies. , Through the new collaboration, ...
(Date:2/9/2016)... FALLS, N.J. , Feb. 9, 2016 /PRNewswire/ ... a biotechnology company specializing in the development and ... health of damaged tissues and organs, recently reported ... for the first quarter of 2016. ... began the new 2015 fiscal year in the ...
(Date:2/9/2016)... ... February 09, 2016 , ... Tunnell Consulting, Inc. announced that Frédéric ... he will focus on acquiring new accounts and work closely with existing Tunnell clients ... “Fred brings to our European clients more than 15 years of experience in the ...
(Date:2/9/2016)... 2016  DNAtrix, a clinical stage, biotechnology ... that its lead product, DNX-2401, has been ... orphan medicinal product for the treatment of ... strikes approximately 25,000 people a year in ... http://photos.prnewswire.com/prnh/20160208/330986LOGO --> http://photos.prnewswire.com/prnh/20160208/330986LOGO ...
Breaking Biology Technology: