This name follows from the previous naming convention used by HDTV and SDTV formats, which refer to a format by the number of pixels/lines along the vertical axis (such as "1080p" for 1920 × 1080 progressive scan, or "480i" for the 480-line interlaced SDTV formats) rather than the horizontal pixel count (≈4000 or "4K" for 3840 × 2160). Some 4K resolutions, like 3840 × 2160, are often casually referred to as 2160p. : 9 Since the resolution in CEA's definition is only a minimum requirement, displays with higher resolutions such as 4096 × 2160 or 5120 × 2880 also qualify as "Ultra HD" displays, provided they meet the other requirements. The CEA definition does allow manufacturers to use other terms-such as 4K-alongside the Ultra HD logo. Capable of processing images according to the color space defined in ITU-R BT.709.At least one HDMI input capable of supporting 3840 × 2160 at 24, 30, and 60 Hz progressive scan (though not necessarily with RGB / Y′C BC R 4:4:4 color), and HDCP 2.2.Support for color depth of 8 bpc (24 bit/px) or higher.CEA defines an Ultra HD product as a TV, monitor, or projector with the following characteristics: In October 2012, the Consumer Electronics Association (CEA) announced their definition of the term Ultra High-Definition (or Ultra HD) for use with marketing consumer display devices. In some of ITU's other standards documents, the terms "UHDTV1" and "UHDTV2" are used as shorthand. Īlthough the UHDTV standard does not define any official names for the formats it defines, ITU typically uses the terms "4K", "4K UHD", or "4K UHDTV" to refer to the 3840 × 2160 system in public announcements and press releases ("8K" for the 7680 × 4320 system).
It adopts the same image parameters defined in SMPTE ST 2036-1. In 2012, the International Telecommunication Union, Radiocommunication Sector published Recommendation ITU-R BT.2020, also known as the Ultra High Definition Television ( UHDTV) standard. UHDTV1 systems are permitted to use BT.709 color primaries up to 60 Hz. These are the same characteristics later standardized in ITU-R BT.2020.
This specification establishes standardized 2K and 4K container formats for digital cinema production, with resolutions of 2048 × 10 × 2160 respectively.
In 2005, Digital Cinema Initiatives (DCI), a prominent standards organization in the cinema industry, published the Digital Cinema System Specification. While typically referring to motion pictures, some digital camera vendors have used the term "4K photo" for still photographs, making it appear like an especially high resolution even though 3840×2160 pixels equal approximately 8.3 megapixels, which is not especially high for still photographs. The terms "4K" and "Ultra HD" are used more widely in marketing than "2160p". : 2 Several different 4K resolutions have been standardized by various organizations. The term "4K" is generic and refers to any resolution with a horizontal pixel count of approximately 4,000. 1.1 DCI Digital Cinema System Specification.