We measure the Absolute Color Accuracy of the display with proprietary sets of 41 Reference Colors for each Standard Color Gamut. The results are plotted on CIE 1976 Uniform Color Diagrams for each Gamut below.
41 Reference Colors for the new wide DCI-P3 Color Gamut Standard
Figure 2a
below shows 41 Reference Colors for the
new wide DCI-P3 Color Gamut as White, Gray, and Black circles.
The 10 Black circles on the outer triangle
are the 100% fully Saturated Colors on the periphery.
The 3 inner sets of Gray triangles are the 25%, 50% and 75% Saturated Colors
between the inner White Point and the 100% Saturated Colors on the periphery.
The White circle is the White Point with 0% Color Saturation.
We have accurately calculated the Colors and Reference Colors for each
of the iPhone X Standard Color Gamuts: DCI-P3 and RGB / Rec.709.
The colors in
Figure 2a
have been calculated to show the true colors
within the DCI-P3 Color Gamut -- the colors shown in most published
Color Gamuts are wildly incorrect.
For an in-depth discussion and analysis of all the
Standard Color Gamuts see this
article.
Note that in order to see the true DCI-P3 colors in Figure 2a your display must support the DCI-P3 Color Gamut - if not then you will instead see the color saturation range that your display can produce, which in most cases will be lower than DCI-P3.
Note that Complementary Colors lie directly across from one another through the White Point.
The 4 sets of triangles are the 25% 50% 75% and 100% Saturated Colors.
Uniform Color Diagrams
All color measurements are plotted on 1976 CIE Uniform Color Diagrams
with (u',v') color coordinates.
Note that the older 1931 CIE Diagrams that are published by many reviewers
with (x,y) color coordinates
are highly non-uniform and are meaningless for Color Accuracy.
Also the still widely referenced NTSC Color Gamut is from 1953 and has been
obsolete for over 30 years so it is also meaningless for specifying the
current Color Gamuts now in use.
For an in-depth discussion and analysis of Color Gamuts see this
article.
Absolute Color Accuracy Plots
The iPhone X has 2 Standard Color Gamuts.
Figure 2b
below shows the measured on-screen colors for the
sRGB / Rec.709 Reference Colors.
Figure 2c
below shows the measured on-screen colors for the
DCI-P3 Reference Colors.
Reference Colors and Measured Colors
The
Reference Colors
in
Figures 2b-2c
are all shown as Black circles and the Measured
Colors for the iPhone X are shown as Red circles.
Color Errors smaller than the appropriate JNCD are not visually noticeable.
The 1 JNCD and 3 JNCD Errors are discussed next and are shown in the Figures below.
Just Noticeable Color Difference JNCD
The on-screen colors produced by any display can be measured using a
Spectroradiometer together with our proprietary DisplayMate Test Patterns.
The accuracy of the colors can then be calculated using the
1976 CIE Uniform Chromaticity color space and compared to the
eye's sensitivity to color.
We present the color accuracy and errors here in terms of
MPCD Minimum Perceptible Color Difference or
JNCD Just Noticeable Color Difference,
where 1 MPCD = 1 JNCD = Δ(u'v') = 0.0040 on the
CIE 1976 Uniform Chromaticity Scale.
Color differences less than 1 JNCD are visually indistinguishable, while values greater than 1 JNCD are visually noticeable when the two colors are touching on-screen. When the colors are not touching and are further apart, the visual threshold for Just Noticing a Color Difference is higher. Here we will use 3 JNCD for the threshold of a visually noticeable display color difference. The 3 JNCD color difference is shown in the Figures below. Any Display Color Error less than 3 JNCD on a display is not visually noticeable and appears perfectly accurate to the eye. For an in-depth discussion and analysis of Absolute Color Accuracy see this article.
The iPhone X provides an accurate color match to the sRGB / Rec.709 Standard Color Gamut.
Figure 2c. DCI-P3 Absolute Color Accuracy Plots
The iPhone X provides an accurate color match to the DCI-P3 Standard Color Gamut.
