出版社：The Institute of Image Information and Television Engineers
摘要：This paper describes two experiments that were conducted to evaluate the required luminance of the black level on liquid crystal displays (LCDs) as a function of the average luminance of a displayed image, the screen illuminance and angular screen size. In the first experiment, 18 subjects adjusted the luminance level of the black region of various still video images, which had different average luminance levels, until they perceived them as black. The results revealed that the required luminance of the black level of an LCD as a function of the average luminance of a displayed image corresponds to the following formula: BL 1= 0.137× AL 0.46. BL 1 is the luminance of the level perceived as black and AL is the average luminance of the displayed image. In the second experiment, 22 subjects adjusted the luminance of a black region embedded in the center of a screen with uniform luminance, under different screen illuminance levels and angular screen sizes, until they perceived it as black. The results revealed that the required luminance of the black level of an LCD as a function of the screen illuminance and background luminance of the black region corresponds to the following formula: log BL 2=0.44 log Ei +0.62 log Lbg −1.8. BL 2 is the luminance of the level perceived as black, Ei is the screen illuminance level and Lbg is the background luminance of the black region. The angular size of the screen did not influence the required luminance of the black level of the LCDs.
