Subjective quality factor revisited: a unification of objective sharpness measures

Bror O. Hultgren

doi:10.1117/12.19688

1 October 1990 Subjective quality factor revisited: a unification of objective sharpness measures

Bror O. Hultgren

Proceedings Volume 1249, Human Vision and Electronic Imaging: Models, Methods, and Applications; (1990) https://doi.org/10.1117/12.19688
Event: Electronic Imaging: Advanced Devices and Systems, 1990, Santa Clara, CA, United States

Abstract

A number of observer based objective measures of image sharpness have been proposed: Higgins, Granger, Cohen & Carison and Barten. Many of these measures, seemingly different in concept, are highly correlated with the psychovisual perception of sharpness. We re-examine the basis for these sharpness measures, and will show that: The signal power spectra of a number of real scenes exhibit a 1/u2 dependence. The corresponding amplitude spectra can be interpreted as the frequency disiribution of spatial frequency content in average scenes. The relationship of these results to simple models of image structure will be discussed. The log spatial integration used in all the measures is equivalent to performing a linear spatial frequency integration with a weighting function (1/u) given by the frequency of occurrence of information in real scenes. While the forms of the visual MTF are substantially different, the measures belong to a class of generalized log frequency sharpness measures that, for equivalent viewing conditions, provide equivalent objective measures of sharpness. The linear dependence of subjective sharpness with the generalized SQF makes this class of sharpness measures a useful tool for product development in both the photographic and display industries.

Citation Download Citation

Bror O. Hultgren "Subjective quality factor revisited: a unification of objective sharpness measures", Proc. SPIE 1249, Human Vision and Electronic Imaging: Models, Methods, and Applications, (1 October 1990); https://doi.org/10.1117/12.19688

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available