Physical and psychophysical evaluation of CRT noise performance

摘要

Abstract: This paper presents the results of both physical and psychophysical evaluations of the limiting noise of high resolution CRTs at luminance levels from 0.83 to 87.5 ft-L. The study concentrated on the effect of CRT noise on the human observer's ability to detect small low contrast objects displayed on the CRT. Temporal as well as spatial noise of the CRT was determined physically with the aid of a photomultiplier-based evaluation system. Just- Noticeable-Differences (JNDs) were determined psychophysically using various test patterns and human observers. It was found that the application of the Rose model can be extended from purely photon noise to other noises, particularly those exhibited by CRTs. The results demonstrate a close correlation between physical and psychophysical evaluation: For the luminance levels under consideration, the detection of the human observers is limited by the spatial noise (phosphor granularity); the temporal noise plays a role only at low luminance levels. There is a direct relationship between the JND and the CRT noise. This result implies that for the luminance levels investigated, an optimal display function can be calculated using the results of a fairly easy physical measurement of noise. !