Perception-based Correlated Color Temperature

Abstract

The correlated color temperature (CCT) is widely used to describe the colors of display whites. The users can easily estimate the color of the display white based on CCT information. High CCT such as 7,000K means blush white and low CCT such as 4,000K means yellowsh white. The original definition of CCT was ‘the temperature of the Planckian radiator whose perceived colour most closely resembles that of a given stimulus at the same brightness and under specified viewing conditions’ but has been changed as ‘temperature of the Planckian radiator having the chromaticity nearest the chromaticity associated with the given spectral distribution on a diagram where the (CIE 1931 standard observer based) u', 2/3v' coordinates of the Planckian locus and the test stimulus are depicted’ because current CCT calcuation method doesn't match with the visual appearance. The previous study showed that CCT is highly correlated with warm-cool feeling of the white color, where warm-cool feeling is determined based on hue perception mainly. A series of hue perception experiments using the color stimuli near Planckian locus were conducted and the results showed that the orthogonal line from the Planckian locus in CIE u'v' chromaticity diagram can be used as the perception-based iso-CCT.