Comparison of Perceived Brightness and Colorfulness for Different Display Technologies

Modern displays are based on liquid crystals, organic emitters, quantum dots or micro-LEDs. These technologies have different color coordinates so that images are rendered differently. Especially in cars, different displays should be calibrated to the same colors, but often a manual correction is required. This is due to the Helmholtz-Kohlrausch (HK) effect which describes the perceived brightness depending on color: Higher saturated colors are perceived brighter. This also holds if the same color is shown with different gamut. We study the HK effect for 4 different display technologies and measured all in terms of luminance, gamma, color coordinates, and gamut for calibration. Calibrated images with the same color coordinates and luminance are compared by subjects using four identical PCs for driving the 2x2 displays to avoid any influence of the graphic adapter. We performed a user study with about 20 subjects where the subjects judge on different test patterns (e. g. white, RGBCMY, photos). The subjects rated all displays for each image e. g. from brightest to darkest. We present our results incl. an extension of CIELAB by HK correction. This helps to ease display calibration. 34 lle Wahrnehmung T M. Hanft T