A new research paper looks at a novel method for visualizing color gamuts in display technology. The study introduces the gamut ring intersection technique, which transforms complex 3D color space data into more intuitive 2D visualizations. This approach allows researchers and display engineers to better understand and compare how different display standards perform in reproducing real-world object colors. The authors analyze various color gamuts including Pointer’s real object gamut, the ISO 12640-3 reference color gamut, and the theoretical optimal color gamut, revealing the relative strengths and limitations of current display technologies. Their findings show that while the BT.2020 UHDTV gamut covers most object colors, even it falls short of the optimal color gamut, suggesting future directions for display development.
The paper is the work of six display industry experts: Kenichiro Masaoka (NHK Foundation), Euan Smith (42 Technology), Karl Lang (Lumita), Brian Berkeley (Highlight Display), Johan Bergquist, and John Penczek (University of Colorado Boulder). All authors are active members of display standards organizations including SID, ICDM, and IEC committees, bringing significant expertise to this research on color reproduction capabilities.
At its core, the research addresses a fundamental challenge in display technology: how to meaningfully represent and compare the three-dimensional nature of color reproduction capabilities in a way that’s both comprehensive and comprehensible.
The authors begin by highlighting how traditional visualization methods like chromaticity diagrams are inadequate because they exclude luminance information, which is crucial for fully understanding color reproduction. They note that industry practices for measuring and describing color gamuts have been inconsistent, leading to misunderstandings and biased claims, even in scientific communications.
To address this problem, the researchers developed a technique called gamut rings to transform complex 3D color gamut data into more intuitive 2D visualizations. This method divides a color gamut solid into 10 segments based on lightness (L*) levels and transforms these into rings that clearly show how color capabilities vary across different lightness, chroma, and hue values. Building on this, they introduce gamut ring intersection as a way to visualize how much of one color gamut is covered by another, making it easier to evaluate display performance across different color regions.
For their analysis, the researchers selected six different color gamuts to compare: Pointer’s real object gamut (OBJ) based on measured real-world object colors; ISO 12640-3 reference color gamut (REF), a standardized reference; the optimal color gamut (OPT), representing the theoretical maximum possible object color gamut; and three display standards – BT.709 HDTV gamut (HD), DCI-P3 gamut (DCI) used in digital cinema, and BT.2020 UHDTV gamut (UHD) used in ultra-high-definition TV.
Through their comparative analysis, the researchers made several important discoveries. They found that the BT.2020 UHDTV gamut, while offering good coverage of real object colors, still falls short of the theoretical optimal color gamut, covering about 74% of it. The DCI-P3 gamut shows limitations in cyan-to-green regions compared to real object colors. Meanwhile, the BT.709 HDTV gamut is considerably limited in reproducing many real-world object colors, particularly outside the blue primary region. Interestingly, the ISO 12640-3 reference color gamut appears to be larger than expected, potentially overestimated, as it partially exceeds the theoretical optimal color gamut. Overall, their analysis reveals that all examined trichromatic display systems using RGB primaries are insufficient to completely reproduce optimal colors.
The paper also discusses several limitations of current approaches and suggests future improvements. The authors point to the need for better sampling methods for display color gamuts, addressing observer metamerism (differences in color perception between individuals), developing advanced color appearance models, creating methods for measuring HDR displays, and redefining object color databases with spectral data.
Reference
Masaoka K, Smith E, Lang K, Berkeley B, Bergquist J, Penczek J. Visualization of reproducible object colors in standard color spaces using the gamut ring intersection. J Soc Inf Display. 2025. https://doi.org/10.1002/jsid.2031
