2021 High-Dynamic Range (HDR) Progress Report

Timo Kunkel, Patrick Griffis

• Since its introduction to the consumer market in 2015, high-dynamic range, better known by its acronym “HDR,” has established itself as a foundational component when looking at the aspects defining today’s image fidelity. This three-letter acronym “HDR” has become synonymous with brighter, more colorful pixels also known as (aka) “better pixels” enabled by a larger color palette that can better utilize the perceptual capability of human vision. SMPTE played a key role in enabling the HDR ecosystem with the standardization of an electro-optical transfer function (EOTF) based on the contrast sensitivity of the human visual system (HVS). This standard, ST 2084:2014, or more commonly “PQ” (for perceptual quantizer) establishes a practical maximum luminance range of 0–10,000 cd/m² for entertainment purposes much like 20 Hz to 20 kHz defines a practical frequency range for audio reproduction. Note that candelas/m² is a technical term for the perceived luminous intensity of light weighted by the HVS spectral response and is often colloquially referred to as “nits”—a term believed to come from the Latin word nitēre, “to shine.”