4K resolution, also called 4K, refers to a horizontal resolution in the order of 4,000 pixels. Several 4K resolutions exist in the fields of digital television and digital cinematography. In television and consumer media, 4K UHD or UHD-1 is the dominant 4K standard. In the movie projection industry, Digital Cinema Initiatives (DCI) is the dominant 4K standard. By 2015, 4K television market share had increased greatly as prices fell dramatically during 2014 and 2015. By 2025, more than half of U.S. households are expected to have a 4K-capable TV (2160p), which would be a much faster adoption rate than that of Full HD (1080p).
There are three main 4K resolution standards:
- UHD-1, or ultra-high-definition television (UHDTV), is the 4K standard for television and computer monitors. UHD-1 is also called 2160p as it has a resolution of 3840 × 2160 (16:9, or approximately a 1.78:1 aspect ratio), which is twice the horizontal and vertical resolution of 1080p, or three times the horizontal and vertical resolution of 720p. UHD-1 is used in consumer television and other media, e.g. video games.
- UW4K is the ultra-wide 4K standard, with a resolution of 3840 × 1600, and an aspect ratio of 12:5 (2.4:1, or 21.6:9) This resolution is most commonly used on Ultra HD Blu-ray discs, and PC gaming monitors.
- DCI 4K which has a resolution of 4096 × 2160 pixels (256:135, approximately a 1.9:1 aspect ratio). This standard is only used in the film and video production industry. The DCI 4K standard has twice the horizontal and vertical resolution of DCI 2K.
Many manufacturers may advertise their products as UHD 4K, or simply 4K, when the term 4K is traditionally reserved for the cinematic, DCI resolution. This has the potential to cause confusion for consumers.
YouTube and the television industry have adopted UHD-1 as their 4K standard. As of 2014[update], 4K content from major broadcasters remains limited. On April 11, 2013, Bulb TV created by Canadian serial entrepreneur Evan Kosiner became the first broadcaster to provide a 4K linear channel and VOD content to cable and satellite companies in North America. The channel is licensed by the Canadian Radio-Television and Telecommunications Commission to provide educational content. However, 4K content is becoming more widely available online including on YouTube, Netflix and Amazon. By 2013, some UHDTV models were available to general consumers in the range of US$600. As of 2015[update], prices on smaller computer and television panels had dropped below US$400. DVB expects UHD-1 Phase 2 services to be introduced by broadcasters from 2017, with features such as High Dynamic Range (using HLG and PQ at 10 or 12 bits), Wide Color Gamut (BT. 2020/2100 colorimetry), and High Frame Rate (up to 120 Hz). 
The first commercially available 4K camera for cinematographic purposes was the Dalsa Origin, released in 2003. 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 started to use the VP9 video compression standard, saying that it was more suitable for 4K than High Efficiency Video Coding (HEVC); VP9 is being developed by Google, which owns YouTube.
Sony is one of the leading studios promoting UHDTV content, as of 2013[update] 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 (~40GB), 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.
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.
In 2016, Sony and Microsoft released the PlayStation 4 Pro and Xbox One S, respectively, both of which are video game consoles that support 4K streaming and gaming; the Xbox One S also features an Ultra HD Blu-ray disc drive.
Home video projectionEdit
|This section may need to be rewritten entirely to comply with Wikipedia's quality standards. (August 2017)|
Though experiencing rapid price drops beginning in 2013 for viewing devices, the home cinema digital video projector market saw little expansion, with only a few manufacturers (only Sony as of 2015[update]) offering limited 4K-capable lineups, with native 4K projectors commanding five-figure price tags well into 2015 before finally breaking the US$10,000 barrier. Critics state that at normal direct-view panel size and viewing distances, the extra pixels of 4K are redundant at the ability of normal human vision. Whereas, projection home cinemas employ much larger screen sizes without necessarily increasing viewing distance to scale. JVC has used a technique known as "e-shift" to extrapolate extra pixels from 1080p sources to display 4K on screens through upscaling or from native 4K sources at a much lower price than native 4K projectors. This technology of non-native 4K entered its fourth generation for 2016. JVC used this same technology to provide 8K flight simulation for Boeing that met the limits of 20/25 visual acuity.
Pixel shifting as described here, was pioneered in consumer space by JVC, and later, in commercial space by Epson. That said, it isn't the same thing as "true" 4K. More recently we now have DLP projectors claiming 4K UHD (which the JVCs and Epsons do not even attempt to claim). Here's what need to know, to understand what's going on, and what's really best:
First, to confirm DCI (movie theaters) is 4096×2160, while "true" 4K is 3840×2160, talking a slight difference in aspect ratio, rather than a significant difference in resolution. In traditional displays, such as LCD or OLED, talking 3840 pixels across the screen - with each pixel being 1/3840th of the screen width. They do not overlap - if they did, detail would be reduced. The diameter if each is basically 1/3840th of the screen width or 1/2160th of the screen height - either gives the same size pixel.
That 3840×2160 works out to 8.3 megapixels, the official resolution of 4K UHD (and therefore Blu-ray UHD discs).
But the 4K UHD standard doesn't seem to care how large the pixels are, so a 4K UHD projector (Optoma, BenQ, Dell, others) counts, because these projectors have a 2718×1528 pixel structure. Those projectors process the true 4K of data, and figure out the best way to handle it with overlapping pixels, which is what pixel shifting is all about. Unfortunately, each of those pixels is far larger, each one has 50% more area than true 4K. Those pixel shifting projectors fire a pixel, shift it up to the right, by a half diameter, and fire it again, with modified data, but that second firing overlaps the first.
In other words pixel shifting is not capable of producing adjacent vertical lines of RGBRGB or any other colors where each line is pixel (1/3840th) wide. Adjacent red and green pixels would end up looking like yellow. with a fringe on one side of red, on the other of green - except that the next line of pixels will be overlapping as well, changing the color of that fringe. Simply stated, there is no way 4K UHD, or 1080p pixel shifting can reveal the fine detail of a true 4K projector such as those Sony ships (business, education and home markets). Also JVC has one true 4K projector priced $35,000 (as of mid-2017).
So while 4K UHD sounds like it was going to have pixel structures with 1/4 the area of 1080p, that's just not going to happen with pixel shifting.
Only a true 4K projector will offer that level of resolution. That should help explain why "true" 4K projectors cost so much more than 4K UHD projectors with otherwise similar feature sets. Getting smaller pixel, finer resolution, no compromising of detail or color from overlapping pixels.
By comparison the slight difference in aspect ratio between DCI and 3840×2160 pixel displays without overlap is insignificant relative to the amount of detail that can be seen.
In November 2014, United States satellite provider DirecTV became the first pay TV provider to offer access to 4K content, although limited to selected video-on-demand films. In August 2015, British sports network BT Sport launched a 4K feed, with its first broadcast being the 2015 FA Community Shield football match. Two production units were used, producing the traditional broadcast in high-definition, and a separate 4K broadcast. As the network did not want to mix 4K footage with upconverted HD footage, this telecast did not feature traditional studio segments at pre-game or half-time, but those hosted from the stadium by the match commentators using a 4K camera. BT envisioned that if viewers wanted to watch studio analysis, they would switch to the HD broadcast and then back for the game. Footage was compressed using H.264 encoders and transmitted to BT Tower, where it was then transmitted back to BT Sport studios and decompressed for distribution, via 4K-compatible BT TV set-top boxes on an eligible BT Infinity internet plan with at least a 25 Mbit/s connection.
In late 2015 and January 2016, three Canadian television providers – including Quebec-based Videotron, Ontario-based Rogers Cable, and Bell Fibe TV, announced that they would begin to offer 4K compatible set-top boxes that can stream 4K content to subscribers over gigabit internet service. On October 5, 2015, alongside the announcement of its 4K set-top box and gigabit internet, Canadian media conglomerate Rogers Communications announced that it planned to produce 101 sports telecasts in 4K in 2016 via its Sportsnet division, including all Toronto Blue Jays home games, and "marquee" National Hockey League games beginning in January 2016. Bell Media announced via its TSN division a slate of 4K telecasts to begin on January 20, 2016, including selected Toronto Raptors games and regional NHL games. 
On January 14, 2016, in cooperation with BT Sport, Sportsnet broadcast the first ever NBA game produced in 4K – a Toronto Raptors/Orlando Magic game at O2 Arena in London, England. On January 20, also during a Raptors game, TSN presented the first live 4K telecast produced in North America. Three days later, Sportsnet presented the first NHL game in 4K.
Dome Productions, a joint venture of Bell Media and Rogers Media (the respective owners of TSN and Sportsnet), constructed a "side-by-side" 4K mobile production unit shared by Sportsnet and TSN's first 4K telecasts; it was designed to operate alongside a separate HD truck and utilize cameras capable of output in both formats. For the opening game of the 2016 Toronto Blue Jays season, Dome constructed "Trillium" – a production truck integrating both 4K and 1080i high-definition units. Bell Media's CTV also broadcast the 2016 Juno Awards in 4K as the first awards show presented in the format.
In February 2016, Univision trialed 4K by producing a closed circuit telecast of a football friendly between the national teams of Mexico and Senegal from Miami in the format. The broadcast was streamed privately to several special viewing locations. Univision aimed to develop a 4K streaming app to publicly televise the final of Copa América Centenario in 4K. In March 2016, DirecTV and CBS Sports announced that they would produce the "Amen Corner" supplemental coverage from the Masters golf tournament in 4K.
|Format||Resolution||Display aspect ratio||Pixels|
|Ultra-high-definition television||3840 × 2160||1.78:1 (16:9)||8,294,400|
|Ultra-wide-television||3840 × 1600||2.4:1 (12:5)||6,144,000|
|DCI 4K (native resolution)||4096 × 2160||1.90:1 (256:135)||8,847,360|
|DCI 4K (CinemaScope cropped)||4096 × 1716||2.39:1 (1024:429)||7,028,736|
|DCI 4K (flat cropped)||3996 × 2160||1.85:1 (999:540)||8,631,360|
4K UHD is a resolution of 3840 pixels × 2160 lines (8.3 megapixels, aspect ratio 16:9) and is one of the two resolutions of ultra high definition television targeted towards consumer television, the other being 8K UHD which is 7680 pixels × 4320 lines (33.2 megapixels). 4K UHD has twice the horizontal and vertical resolution of the 1080p HDTV format, with four times as many pixels overall. Likewise, 4K UHD has three times the horizontal and vertical resolution of the 720p format, with nine times as many pixels overall.
The Digital Cinema Initiatives consortium established a standard resolution of 4096 pixels × 2160 lines (8.8 megapixels, aspect ratio 256:135) for 4K movie projection. This is the native resolution for DCI-compliant 4K digital projectors and monitors; pixels are cropped from the top or sides depending on the aspect ratio of the content being projected. The DCI 4K standard has twice the horizontal and vertical resolution of DCI 2K, with four times as many pixels overall. DCI 4K does not conform to the 16:9 aspect ratio, so it is not a multiple of the 1080p display.
4K digital movies may be produced, scanned, or stored in a number of other resolutions depending on what storage aspect ratio is used. In the digital cinema production chain, a resolution of 4096 × 3112 is often used for acquiring "open gate" or anamorphic input material, a resolution based on the historical resolution of scanned Super 35mm film.
YouTube, since 2010, and Vimeo allow a maximum upload resolution of 4096 × 3072 pixels (12.6 megapixels, aspect ratio 4:3). Vimeo's 4K content is currently limited to mostly nature documentaries and tech coverage.
YouTube added support for up to 8K 7680×4320 video content in June 2015.
The main advantage of recording video at the 4K standard is that fine spatial detail is resolved well. If the final video quality is reduced to 2K from a 4K recording more detail is apparent than would have been achieved from a 2K recording. Increased fineness and contrast is then possible with output to DVD and Blu-ray. Some cinematographers choose to record at 4K when using the Super 35 film format to offset any resolution loss which may occur during video processing.
- Goulekas, Karen (2001). Visual Effects in a Digital World. Morgan Kaufmann. p. 587. ISBN 9780080520711.
4K resolution: A general term referring to any digital image containing an X resolution of approximately 4000 pixels.
- "First Quarter 2015 4K TV Growth Strong As Overall LCD TV Shipments Slow, IHS Says". IHS Inc. 8 June 2015. Retrieved November 24, 2015.
- Mark Hoelzel (2 September 2014). "4K TV Shipments Are Ramping Up Much Faster Than HD TV Did In The Past". Business Insider. Retrieved November 24, 2015.
- Thomas, Alexander. "Just how useful is 2160p aka 4K?".
- "4K vs. UHD: What’s the difference? – ExtremeTech".
- Denison, Caleb (15 Jan 2014). "Your 1080p TV is old already: Everything you need to know about Ultra HD 4K". Digital Trends. Retrieved 31 May 2014.
- "The Best TV Deserves The Best TV – Samsung". Samsung Electronics America.
- "X Series – 4K TV : BRAVIA™ LED TV, Full HD Television, 4K TV, 3D TV : Sony India". Sony India.
- "Leading Television Industry Players Line Up To Support '4K Ultra HD'" (Press release). Consumer Electronics Association. 11 November 2014. Retrieved 18 December 2014.
- Lowensohn, Josh (9 July 2010). "YouTube now supports 4k-resolution videos". Tech Culture. CNET. Retrieved 18 December 2014.
- Brown, Heather (16 October 2014). "Good Question: When Will We See Broadcasts In 4K?". Local. CBS Minnesota. Retrieved 18 December 2014.
- "Canadian Serial Entrepreneur to Launch First 4,000-pixel Television Signal, Bulb TV". 11 April 2013. Retrieved 12 November 2013.
- "Young media mogul granted TV licence". 12 April 2013. Archived from the original on 14 May 2013. Retrieved 12 November 2013.
- "Canadian Cat B Channel Plans 4K Video Feed". 16 April 2013. Retrieved 12 November 2013.
- "Bulb TV to turn on 4k". 12 April 2013. Retrieved 12 November 2013.
- "Broadcasting Decision CRTC 2012-268". 4 May 2012.
- Luckerson, Victor (12 November 2014). "Amazon Will Stream in Ultra-High Def 4K by January". Tech Companies. Time. Retrieved 18 December 2014.
- Anderson, Jim (17 December 2014). "4K Ultra HD, High Quality: Red". YouTube. Retrieved 18 December 2014..
- Cox, Joe (27 June 2013). "Seiki launches 39in 4K TV for $699". What Hi-Fi. Haymarket. Retrieved 21 January 2014.
- Greenwald, Will (28 June 2013). "Seiki SE39UY04". PC Mag. Ziff Davis. Retrieved 21 January 2014.
- "Viewsonic monitor". Newegg.com. Retrieved 21 November 2015.
- Frost, Jacqueline B (2009). Cinematography for Directors: A Guide for Creative Collaboration. Michael Wiese Productions. p. 199. ISBN 1-61593019-1. Retrieved 21 January 2014.
- "Dalsa Origin was the very first commercially obtainable 4K Resolution". epfilms. Retrieved 19 June 2016.
- Teoh, Vincent (25 December 2013). "YouTube Adds "2160p 4K" Option To Video Quality Settings". HDTVTest. Retrieved 24 May 2014.
- "Youtube puts in new 2160p 4K option for video-settings". Neo win. Retrieved 24 July 2014.
- Truong, Alice (August 6, 2013). "4K is already playing at a theater near you, but you probably didn’t even notice". Digital Trends. Designtechnica. Retrieved 24 May 2014.
- "Sony Unveils New "4k" Digital Cinema Projector" (press release). Projector Central. June 3, 2004. Retrieved 24 May 2014.
- Quick, Darren (May 31, 2012). "Sony releases world's first 4K home theater projector". Gizmag. Retrieved 24 May 2014.
- Denison, Caleb (September 4, 2013). "Sony feeds starving 4K early adopters with over 70 titles of 4K movies and TV shows". Digital Trends. Retrieved 31 May 2014.
- "Breaking Bad is now streaming in 4K on Netflix", Gizmodo.
- Katzmaier, David (8 April 2014). "Netflix begins 4K streams". CNET. Retrieved 30 May 2014.
- Kerr, Dara (17 December 2013). "Amazon Studios to begin shooting original series in 4K". CNET. Retrieved 30 May 2014.
- Katzmaier, David (March 30, 2015). "Sony VPL-VW350ES review". CNET. Retrieved December 7, 2015.
- Pendlebury, Ty (September 26, 2013). "JVC debuts cheaper pseudo-4K projectors". CNET. Retrieved December 7, 2015.
- "DLA-X550R Overview". JVC. Retrieved December 7, 2015.
- Silva, Robert (October 16, 2015). "JVC Intros 4th Generation e-Shift 4K Projectors at CEDIA 2015". About.com. Retrieved December 7, 2015.
- Cohen, Steven (October 19, 2015). "JVC Readies New eShift 4K D-ILA Projectors with HDR". High-Def Digest. Retrieved December 7, 2015.
- Turnbull, Grant (November 25, 2015). "I/ITSEC 2015: New training approaches for Boeing". Shephard Media. Retrieved December 7, 2015.
- "DirecTV launches 4K exclusive to Samsung TVs". CNET. Retrieved 15 April 2016.
- "BT Sport Ultra HD Made Even My Mum Want to Watch 4K Football". Gizmodo UK. Retrieved 24 January 2016.
- "Behind the scenes of BT Sport's 4K Ultra HD revolution". Techradar. Retrieved 23 January 2016.
- "4K content becomes a reality in Canada". Toronto Star. Retrieved 21 January 2016.
- "Why you should add a 4K television to your holiday shopping list". The Globe and Mail. Retrieved 16 January 2016.
- "TSN delivers live 4K broadcast of Raptors-Celtics". TSN.ca. Retrieved 15 January 2016.
- "Rogers leveraging sports ownership to push 4K TV". The Globe and Mail. Retrieved 6 October 2015.
- "Rogers announces Ignite Gigabit internet, 4K sports broadcasts". CBC News. Retrieved 16 January 2016.
- "4K Sports Descend on Canada: First-Ever Live 4K NBA Game From London Kicks Off Parade of 4K Content". Sports Video Group. Retrieved 16 January 2016.
- "Sportsnet to produce first NHL game in 4K". Sportsnet.ca. Rogers Media. Retrieved 24 January 2016.
- "Dome Productions Preps for Arrival of Live 4K Sports in Canada". Sports Video Group. Retrieved 16 January 2016.
- "Dome, Rogers Sportsnet Develop Single Production Solution for UHD/HD". Sports Video Group. Retrieved 21 April 2016.
- "Juno Awards 2016: The Weeknd, Bieber, Dean Brody among winners". CBC News. Retrieved 21 April 2016.
- "SVG Exclusive: Univision to produce Copa América Centenario final in 4K". Sports Video Group Europe. Retrieved 12 March 2016.
- "How Univision is beating the competition to 4K sports streaming". Engadget. Retrieved 12 March 2016.
- "Mexico vs Senegal friendly is a test for 4K". TechRadar. Retrieved 12 March 2016.
- "DirecTV's first live 4K show is the Masters golf tournament". Engadget. Retrieved 12 March 2016.
- "The Masters in 4K: DirecTV, CBS Sports Tee Up First Live 4K UHD Broadcast in U.S.". Sports Video Group. Retrieved 12 March 2016.
- "The Ultimate Guide to 4K Ultra HD", Ultra HDTV Magazine, retrieved 2013-10-27.
- "Ultra High Definition Television: Threshold of a new age". ITU. 2012-05-24. Retrieved 2012-08-18.
- David S. Cohen (1 August 2013). "Ultra-HD TV Faces Bandwidth Challenge to Get Into Homes". variety.com. Variety Media. Retrieved 30 May 2014.
- Pullen, John Patrick (December 8, 2015). "Everything to Know Before Buying a UHD Television". Time, Inc. Retrieved December 16, 2015.
- "Resolution Table". Resolution Table. Pixar. Retrieved 21 January 2014.
- "4K resolution Definition from PC Magazine Encyclopedia". PC Magazine. 1994-12-01. Retrieved 2010-05-28.
- James, Jack (2006). Digital Intermediates for Film and Video. Taylor & Francis. p. 125. ISBN 0240807022. Retrieved 21 January 2014.
- Jukic, Stephanie. "4K & Ultra HD Resolution". 4K.com. Retrieved 26 November 2014.
YouTube has had a 4K channel running since as early as 2010 and other developments are definitely on the horizon, especially in countries or regions with excellent internet connectivity that goes above the normal speeds available to most people.
- Ramesh Sarukkai (2010-07-09). "What's bigger than 1080p? 4K video comes to YouTube". Archived from the original on 16 July 2011. Retrieved 2011-08-20.
- "Advanced encoding settings". Google. Retrieved 21 January 2014.
- Ohannessian, Kevin. "Where Can You Get 4K Video?". Toms's Guide. Purch, Inc. Retrieved 26 November 2014.
YouTube and Vimeo already stream 4K content. Most of the videos are of the nature/documentary variety, with some tech media coverage thrown in the mix. However, Google recently announced plans to make a much larger selection of 4K video available on YouTube, using its new compression technology, called VP9. If your computer has a powerful graphics card that supports 4K and HDMI version 1.4 or higher, you can connect your computer to a 4K television via an HDMI cable. You will likely need high bandwidth to stream the video without any issues, though neither YouTube nor Vimeo has specified the minimum data speed needed for 4K streaming. In addition, Asus, Dell and Sharp already have 4K computer monitors (with more coming this year) that can be used with your computer to watch 4K content.
- Anderson, Jim. "4K Ultra HD Test, High Quality BLUE". YouTube. Retrieved 1 April 2015.
- Ryan Lawler (25 January 2013). "Next-Gen Video Format H.265 Is Approved, Paving The Way For High-Quality Video On Low-Bandwidth Networks". TechCrunch. AOL. Retrieved 30 May 2014.
- "Naughty America: 4K porn is coming, trailer released", Pocket lint.
- "Payserve Launches 4k Ultra-HD Site, Sindrive". Adult Video News. Retrieved 23 January 2016..
- Wootton, Cliff (2005). A Practical Guide to Video and Audio Compression: From Sprockets and Rasters to Macroblocks. Taylor & Francis. p. 47. ISBN 0-24080630-1. Retrieved 21 January 2014.
- Braverman, Barry (2013). Video Shooter: Storytelling with HD Cameras. CRC Press. pp. 4–18. ISBN 1-13605885-0. Retrieved 21 January 2014.
- Sawicki, Mark (2007). Filming the Fantastic: A Guide to Visual Effects Cinematography. CRC Press. p. 114. ISBN 1-13606662-4. Retrieved 21 January 2014.
- "Axiom Alpha".
- "Zynq-based Axiom Alpha open 4K cine camera proto debuts in Vienna hackerspace". 2014-03-20.
- "Axiom Alpha: Die Open-Hardware-Kamera" [Axiom α: the open hardware camera]. Heise (in German). 2014-05-22.
- What is Ultra HDTV?, Ultra HD TV
- "3D TV is Dead, Long Live 4K", Forbes, Jan 10, 2013
- Gurule, Donn, 4k and 8k Production Workflows Become More Mainstream, Light beam
- What is the meaning of UHDTV and its difference to HDTV?, UHDMI
- "Ultra high resolution television (UHDV) prototype", CD Freaks
- "Just Like High-Definition TV, but With Higher Definition]", The New York Times, Jun 3, 2004
- "Japan demonstrates next-gen TV Broadcast", Electronic Engineering Times.
- "Researchers craft HDTV's successor", PC World (magazine)
- Sugawara, Masayuki (2008), Super Hi-Vision—research on a future ultra-HDTV system (PDF) (technical review), CH: EBU
- Ball, Christopher Lee (Oct 2008), "Farewell to the Kingdom of Shadows: A filmmaker's first impression of Super Hi-Vision television", Musings
- "Visual comparison of the different 4K resolutions", 4k TV
- "Why Ultra HD 4K TVs are still stupid", 4k TV
Official sites of NHKEdit
- Super Hi-Vision, JP: NHK.
- Science & Technical Research Laboratories, JP: NHK.
- Super Hi-Vision research (annual report), JP: NHK STRL, 2009.