Abstract

A theoretical expression is derived for the least distinguishable step in the number of pulses from an area whose image is focused on and measured by a single photoemissive detector. For large numbers of pulses this discrimination step is found to be equal to 6.8 times the rms fluctuation of the number of pulses at the given level. For the threshold step, the 6.8 factor must be replaced by 4.1. The maximum noise-to-signal ratio is computed for the cases of sample and path noise. A formula is found for the total number of discrimination steps in a macrocell whose photon number may vary between two given limits. Satisfactory agreement is found between computed and experimental values found by other researchers for the discrimination step of temperature, the discrimination step for the eye, the number of discrimination steps in a TV picture element and the number of equal lightness steps in a grey sample as given by the formula of the original Munsell system. A theory which assumes that in observing areas of even radiance, the eye adds up the signals from neighboring retinal detectors can explain some experimental data for the eye.

© 1968 Optical Society of America

Full Article  |  PDF Article
Related Articles
The Rose model, revisited

Arthur E. Burgess
J. Opt. Soc. Am. A 16(3) 633-646 (1999)

Gray-scale perceptions calculated: optimum display background luminance

Robert Carter
Appl. Opt. 36(8) 1705-1717 (1997)

Quantum Efficiency of Human Vision

R. Clark Jones
J. Opt. Soc. Am. 49(7) 645-653 (1959)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (49)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription