Let's delve deeply into color volume and what it means

[Robert Zohn]

2017 is the first year we have been discussing and keenly focused on Color Volume. This is because color volume has only become an issue with the new TV System of HDR, WCG, 10-bit and EOTF.

Samsung did an interesting presentation at CES 2017 demonstrating the color volume of their new 2017 Quantum Dot (nano cell) displays that measured the color volume compared to LG's 2016 OLED G6. The measurements showed the new Quantum Dot displays yielding 108% of the P3 color gamut and LG's G6 measured 67% of the P3 color space. The charts showed that in high peak luminance levels Samsung's Q-Dot panel delivered better color fidelity.

One thing we should be considering is that scenes with specular highlights (the highest peak luminance levels) do not have much color in them as they are very bright and the signal is mostly white with some specular highlights using minimal color, like the bright scenes showing direct views of the sun.

LCD/LED displays naturally have a higher peak luminance than any emissive display as individual pixel illumination can't deliver the peak levels of the larger back-lit light sources. Imagine the size of the OLED light valves as the size of a pinhead that make up the 8.3 million pixels of a UHD TV and how much light can be generated from them.

On the other hand, emissive displays with their individual pixel illumination control have the ability to deliver (pixel-by-pixel) pure black and the finite low luminance levels that exploit the new EOTF curve that has been redesigned to match the human vision system of seeing more detail in low luminance levels. EOTF uses most of the displays 10-bit 1024 levels of illumination on the low end and has very minimal power in the peak luminance.

Let's discuss color volume as it relates to the value of the highest peak luminance with a fuller color palette and how that element impacts the overall image quality.