
This study builds upon our previous work, where we analyzed the range of real-world colors and identified images containing colors that exceed the boundaries of legacy color gamuts such as sRGB and DCI-P3, making them difficult for traditional displays to render accurately. In our current research, we conducted a series of visual experiments to evaluate perceptual differences and viewer preferences when such images are displayed on ultra-WCG displays compared to standard-gamut displays. Our findings indicate that observers could consistently distinguish between images shown on an ultra-WCG display and the same images calibrated to sRGB. The perceptual difference between DCI-P3 and ultra-WCG was notably smaller, resulting in lower detection rates that were more contentdependent. Overall, observers showed a strong preference for the ultra-WCG display, regardless of the viewing condition or the image content.

The image qualities of LCD and OLED monitors set to their own default settings were compared using forced-choice experiment method. Both displays’ peak white luminance was around 1,000 cd/m2 and color gamut setting was fixed as DCI-P3 for LCD while OLED’s gamut was set as DCI-P3 or BT.2020. The twelve image quality evaluation keywords were collected through the focus group Interview and eleven HDR video clips were selected as test stimuli. During the experiment, the test video was shown on two displays placed side-by-side and thirteen naïve participants were asked to select the display having the better image quality. The experimental results showed that OLED has higher image quality than LCD does because of higher colorfulness in general. Black luminance level affected the image quality for the dark images but the images having large bright area, colorfulness affected the overall image quality. This result shows that not display technology but the color characteristics affects the image quality.