出版社：The Institute of Image Information and Television Engineers
摘要：Liquid-crystal displays (LCDs) are now widely used as computer display devices. Among them, twisted nematic (TN-mode) and super twisted nematic (STN-mode) displays are the most popular. The spectral transmittance of these LCDs, however, depends on the gray tone level so the gray tone color becomes bluish. We have therefore investigated the quality of the displays and in this study we focus on face color quality. We prepared test images by using a software program to add blue into the image data. Five different bluish levels were used in simulated TN-mode and STN-mode displays. Nine portraits were selected as the testing images. Test participants were asked to judge the quality of the faces according to a five-grade scale and judge the amount of blue according to an impairment scale. These test results show that face color quality is significantly affected by the bluish level of gray tones and that face-color quality is good when no blue is perceived in the face color. We then compared the simulated face color quality with the gray-tone chromaticity of three current TN-mode LCDs, and we found that two of them will be able to display good face colors.
