Legibility Evaluation of Displayed Characters Using a Measure of Detectability of Pictorial Pattern

Abstract

This paper describes an analytical method to evaluate the legibility of displayed characters through detectability of pictorial patterns. In image pickup devices including eyes, shot noise is produced during the process of photoelectric conversion, and result in limited detection of intended pictures. Hence it can be considered that detectability of pictorial pattern is an important element for evaluation of the image quality. From this view point, an analysis is conducted on relationship between the resolution of display and the detectability of displayed Kanji patterns. This analysis is performed on the basis of lijima's picture observation theory. The detectability of each displayed pattern is compared with the result of subjective evaluation of legibility. Consequently, it is shown that the deterioration of legibility of characters which resulted from the resolution of display confirms the change in detectability. By this means, validity evaluation conducted on the legibility of displayed characters through detectability is verified