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Proceedings Paper

Adaptation to blur
Author(s): Michael A. Webster; Shernaaz M. Webster; Jennifer MacDonald; Shrikant R. Bahradwadj
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Paper Abstract

Blur is an intrinsic property of the retinal image that can vary substantially in natural viewing. We examined how processes of contrast adaptation might adjust the visual system to regulate the perception of blur. Observers viewed a blurred or sharpened image for 2-5 minutes, and then judged the apparent focus of a series of 0.5-sec test images interleaved with 6-sec of readaptation. A 2AFC staircase procedure was used to vary the amplitude spectrum of successive test to find the image that appeared in focus. Adapting to a blurred image causes a physically focused image to appear too sharp. Opposite after-effects occur for sharpened adapting images. Pronounced biases were observed over a wide range of magnitudes of adapting blur, and were similar for different types of blur. After-effects were also similar for different classes of images but were generally weaker when the adapting and test stimuli were different images, showing that the adaptation is not adjusting simply to blur per se. These adaptive adjustments may strongly influence the perception of blur in normal vision and how it changes with refractive errors.

Paper Details

Date Published: 8 June 2001
PDF: 10 pages
Proc. SPIE 4299, Human Vision and Electronic Imaging VI, (8 June 2001); doi: 10.1117/12.429515
Show Author Affiliations
Michael A. Webster, Univ. of Nevada/Reno (United States)
Shernaaz M. Webster, Univ. of Nevada/Reno (United States)
Jennifer MacDonald, Univ. of Nevada/Reno (United States)
Shrikant R. Bahradwadj, Medical Research Foundation (India)


Published in SPIE Proceedings Vol. 4299:
Human Vision and Electronic Imaging VI
Bernice E. Rogowitz; Thrasyvoulos N. Pappas, Editor(s)

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