Preferred color gamut boundaries for wide‐gamut and multiprimary displays

Abstract

Preferred chroma enhancement and its dependence on hue are studied in a two-part experiment using a wide-gamut multiprimary display. Earlier research showed a clear dependence on hue but was limited by the gamut of the display it employed; the present work builds on this while easing the gamut constraints. In the first part of the present experiment, a tuning task was used to refine the preference for chroma boost starting with standard-gamut (Rec. 709) images. The overall median preferred boost is roughly 20%, but it is not uniform over hues: the preferred boost for orange, yellow, green, and cyan colors is greater than that for blue, magenta, and red colors. Dependence on image content and observer is noted, though a content-independent chroma boost created by aggregating preference over many images performs well. An adjustment parameter for overall chroma, which incorporates the hue dependence averaged over image content, should be sufficient to handle the vast majority of interobserver variance in preference. In the second part of the experiment, various chroma boost algorithms were evaluated through a paired comparison task. The prescribed hue-dependent chroma boost is preferred over all other variations, and all hue-preserving chroma boost variations are preferred over both colorimetrically accurate and naïve same-drive-signal renderings. The results may be applied in display design to select gamut boundaries that maximize satisfaction over the observer population.

Image quality equivalence between peak luminance and chromaticity gamut

“…In terms of finding a color gamut, preference‐based studies were reported. Murdoch et al claimed that color gamut boundaries for wide gamut and multiprimary displays can be expanded up to 20%, on average, from the standard color gamut, ITU‐Rec.709 [6] . They pointed out that the degree of boosting color gamut depends on not only hue but also image content and observer.…”

Subjective evaluation of natural high‐saturated images on a wide gamut display

“…Previous studies on wide color gamut displays have mainly focused on the preferred chroma of natural images . For example, Murdoch et al investigated preferred levels of chroma using an RGB wide gamut display.…”

“…Previous studies on wide color gamut displays have mainly focused on the preferred chroma of natural images. [2][3][4][5][6] For example, Murdoch et al 4 investigated preferred levels of chroma using an RGB wide gamut display. In the study, natural images with very narrow hue ranges were used, and subjects' task was to select the level of colorfulness that they preferred for each image by changing their CIELAB chroma values.…”