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Defocus Blur

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Computer Vision

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Synonyms

Out of focus blur

Related Concepts

Blur Estimation; Motion Blur

Definition

Defocus blur is a loss of sharpness that occurs due to integrating light over an aperture with a nonzero area, where the light source is off of the image focal plane. The amount of blur that is visible in an image is a function of the lens aperture, the object and focal depth, and the camera pixel (or grain) size.

Background

Image blur can be described by a point spread function (PSF). A PSF models how an imaging system captures a single point in the world – it literally describes how a point spreads across an image. An entire image is then made up of a sum of the individual images of every scene point, where each point’s image is affected by the PSF associated with that point. For an image to be “in focus” means that one ideally does not want any image blur at a particular depth of the scene. Thus, the PSF should be minimal, i.e., a delta function, where each scene point should correspond only to one...

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References

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Author information

Authors and Affiliations

  1. Microsoft Corporation, One Microsoft Way, 98052, Redmond, WA, USA

    Neel Joshi

Authors
  1. Neel Joshi
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Corresponding author

Correspondence to Neel Joshi .

Editor information

Editors and Affiliations

  1. Institute of Industrial Science, The University of Tokyo, Tokyo, Japan

    Katsushi Ikeuchi

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© 2014 Springer Science+Business Media New York

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Joshi, N. (2014). Defocus Blur. In: Ikeuchi, K. (eds) Computer Vision. Springer, Boston, MA. https://doi.org/10.1007/978-0-387-31439-6_511

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