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4K resolution refers to a horizontal display resolution of approximately 4,000 pixels. Digital television and digital cinematography commonly use several different 4K resolutions. In television and consumer media, 3840 × 2160 (4K UHD) is the dominant 4K standard, whereas the movie projection industry uses 4096 × 2160 (DCI 4K).

The 4K television market share increased as prices fell dramatically during 2014 and 2015. By 2020, more than half of U.S. households are expected to have 4K-capable TVs, a much faster adoption rate than that of Full HD (1080p).

History

In 1984, Hitachi released the CMOS graphics processor ARTC HD63484, which was capable of displaying up to 4K resolution when in monochrome mode. The resolution was targeted at the bit-mapped desktop publishing market. The first commercially available 4K camera for cinematographic purposes was the Dalsa Origin, released in 2003. 4K technology was developed by several research groups in universities around the world, such as University of California, San Diego, CALIT2, Keio University, Naval Postgraduate School and others that realized several demonstrations in venues such as IGrid in 2004 and CineGrid. YouTube began supporting 4K for video uploads in 2010 as a result of leading manufacturers producing 4K cameras. Users could view 4K video by selecting "Original" from the quality settings until December 2013, when the 2160p option appeared in the quality menu. In November 2013, YouTube began to use the VP9 video compression standard, saying that it was more suitable for 4K than High Efficiency Video Coding (HEVC). Google, which owns YouTube, developed VP9.

Theaters began projecting movies at 4K resolution in 2011. Sony was offering 4K projectors as early as 2004. The first 4K home theater projector was released by Sony in 2012.

Sony is one of the leading studios promoting UHDTV content, as of 2013 offering a little over 70 movie and television titles via digital download to a specialized player that stores and decodes the video. The large files (≈40 GB), distributed through consumer broadband connections, raise concerns about data caps.

In 2014, Netflix began streaming House of Cards, Breaking Bad, and "some nature documentaries" at 4K to compatible televisions with an HEVC decoder. Most 4K televisions sold in 2013 did not natively support HEVC, with most major manufacturers announcing support in 2014. Amazon Studios began shooting their full-length original series and new pilots with 4K resolution in 2014. They are now currently available though Amazon Video.

In March 2016 the first players and discs for Ultra HD Blu-ray—a physical optical disc format supporting 4K resolution and HDR at 60 frames per second—were released.

On August 2, 2016 Microsoft released the Xbox One S, which supports 4K streaming and has an Ultra HD Blu-ray disc drive, but does not support 4K gaming. On November 10, 2016 Sony released the PlayStation 4 Pro, which supports 4K streaming and gaming, though many games use checkerboard rendering or are upscaled 4K. On November 7, 2017, Microsoft released the Xbox One X, which supports of 4K streaming and gaming, though not all games are rendered at native 4K.