Editing Pixelization

{{Short description|Blurring technique in images or videos}}
{{About|the graphical editing/censorship technique|the undesirable phenomenon in which individual pixels are visible|Pixelation|the stop motion animation technique|Pixilation}}
{{Refimprove|date=December 2008|article on [[Censorship|image censorship]]}}

'''Pixelization''' (in [[British English]] '''pixelisation''') or '''mosaic processing''' is any technique used in editing images or video, whereby an image is blurred by displaying part or all of it at a markedly lower [[Image resolution|resolution]]. It is primarily used for [[censorship]]. The effect is a standard graphics filter, available in all but the most basic [[Raster graphics editor|bitmap graphics editor]]s.

==In media==
Pixelization has also been used for artistic effect, notably in the art print ''The Wave of the Future''<!-- by whom?-->, a reinterpretation of [[Hokusai|Katsushika Hokusai]]'s ''[[The Great Wave off Kanagawa]]''. In this updated print, the image of the large ocean wave shifts from the traditional style of the Japanese [[woodcut]] print to a pixelized image and finally to a [[wireframe model]] [[computer graphics]] image.<ref>vorpal.us: [http://vorpal.us/2007/07/wave-of-the-future-is-now-the-past/ "Wave of the Future is now the Past"]. Retrieved July 13, 2009</ref><ref>vorpal.us: [http://vorpal.us/img/waveofthefuture.jpg "High resolution image of 'Wave of the Future'"]. Retrieved July 14, 2009</ref> ''[[Westworld (film)|Westworld]]'' (1973) was the first feature film to use [[digital image processing]] to pixelize photography to simulate an android's point of view.

The 2010 third-person cover shooter [[Kane & Lynch 2: Dog Days]] also used pixelization for artistic purposes, as nudity and headshots are pixelated in the game, to make the game appear more like [[user-generated content]].

==Alternative techniques==
[[File:Umm Rasas Fisherman.JPG|thumb|The mosaic tiles of this human figure in the Saint Stephen Church in [[Umm ar-Rasas]] in Jordan have been rearranged by [[Aniconism|aniconists]].]]
A black rectangular or square box (known as [[censor bars]]) may be used to occlude parts of images completely (for example, a black bar covering the eyes instead of the entire face being pixelized). Censor bars were extensively used as a graphic device in the January 2012 [[protests against SOPA and PIPA]].

A drawback of pixelization is that any differences between the large pixels can be exploited in moving images to reconstruct the original, unpixelized image;<ref>{{cite journal |last1=Newton |first1=EM |last2=Sweeney |first2=L |last3=Malin |first3=B |title=Preserving privacy by de-identifying face images |journal=IEEE Transactions on Knowledge and Data Engineering |date=Jan 2005 |volume=17 |issue=2 |pages=232–243 |doi=10.1109/TKDE.2005.32 |s2cid=1813467 |url=https://dataprivacylab.org/dataprivacy/projects/video/paper.pdf}}</ref> squinting at a pixelized, moving image can sometimes achieve a similar result. In both cases, integration of the large pixels over time allows smaller, more accurate pixels to be constructed in a still image result. Completely obscuring the censored area with pixels of a constant color or pixels of random colors escapes this drawback but can be more aesthetically jarring.

An additional drawback, when pixelization is used to reduce the repulsing, disturbing or, more generally shocking, aspect of an image, is that all information contained in the pixelized area is lost for the audience.<ref name="BesançonSemmo2019">{{cite journal|last1=Besançon|first1=Lonni|last2=Semmo|first2=Amir|last3=Biau|first3=David|last4=Frachet|first4=Bruno|last5=Pineau|first5=Virginie|last6=Sariali|first6=El Hadi|last7=Soubeyrand|first7=Marc|last8=Taouachi|first8=Rabah|last9=Isenberg|first9=Tobias|last10=Dragicevic|first10=Pierre|title=Reducing Affective Responses to Surgical Images and Videos Through Stylization|journal=Computer Graphics Forum|volume=39|issue=1|year=2019|pages=462–483|issn=0167-7055|doi=10.1111/cgf.13886|doi-access=free}}</ref> Other visual processing techniques can help reduce the shocking aspect of images or videos while preserving most of the information of the media.<ref name="BesançonSemmo2019"/><ref name="BesançonSemmo2018">{{cite book|last1=Besançon|first1=Lonni|last2=Semmo|first2=Amir|last3=Biau|first3=David|last4=Frachet|first4=Bruno|last5=Pineau|first5=Virginie|last6=Sariali|first6=El Hadi|last7=Taouachi|first7=Rabah|last8=Isenberg|first8=Tobias|last9=Dragicevic|first9=Pierre|title=Proceedings of the Joint Symposium on Computational Aesthetics and Sketch-Based Interfaces and Modeling and Non-Photorealistic Animation and Rendering|chapter=Reducing affective responses to surgical images through color manipulation and stylization|year=2018|pages=1–13|doi=10.1145/3229147.3229158|isbn=9781450358927|s2cid=51928057|url=https://hal.inria.fr/hal-01795744/file/Besancon_2018_RAR.pdf}}</ref>

==International legal standards==
[[Nudity]] is obscured on [[Broadcast network|broadcast]] [[television station]]s in the United States. The [[Federal Communications Commission]] states it is a violation of federal law to air obscene, indecent, and profane programming at any time, especially during certain hours. Monetary penalties and revocation of licenses are issued for law breakers.<ref>{{Cite web|date=2010-11-18|title=Obscenity, Indecency and Profanity|url=https://www.fcc.gov/general/obscenity-indecency-and-profanity|access-date=2020-09-17|website=Federal Communications Commission|language=en}}</ref> [[Pornography in Japan|Japanese pornography]] laws require that genitals in films (including animated works) and other forms of adult media (such as [[eroge]], drawings, etc) be obscured. Article 175 of Penal Code (Act No.45 of 1907) still in effect today in Japan forbids any person and imprisons anyone who distributes, sells or displays in public an obscene document, drawing or other objects of such nature.<ref>{{Cite web|title=PENAL CODE (Act No.45 of 1907)|url=http://www.cas.go.jp/jp/seisaku/hourei/data/PC.pdf|quote=Article 175}}</ref> [[censorship in Thailand|In Thailand]], restrictions are placed on television broadcast depiction of cigarettes being smoked,<ref>2Bangkok.com: [http://www.2bangkok.com/2bangkok/Simpsons/SimpsonsSmoking.shtml "Smoking on Thai TV"] {{Webarchive|url=https://web.archive.org/web/20100725160027/http://www.2bangkok.com/2bangkok/Simpsons/SimpsonsSmoking.shtml |date=2010-07-25 }} Retrieved February 15, 2007</ref> alcohol being consumed, or guns being pointed at people. Pixelization is one method of censoring this content.

==See also==
* [[Bleep censor]]
* [[Colour banding]]
* [[Fogging (censorship)]], an alternate technique<!-- Add to Alternative techniques section. -->
* [[Posterization]]
* [[Reverse video]]
* [[Tape delay (broadcasting)]]
* Use of pixelation in camouflage patterns such as [[MARPAT]]

==References==
{{Reflist}}

==External links==
{{Commons category}}
{{Wiktionary|pixelization|pixelisation}}
* [http://www.facepixelizer.com Facepixelizer - Online editor for pixelizing parts of an image]

{{Censorship}}

[[Category:Censorship of broadcasting]]
[[Category:Digital art]]
[[Category:Self-censorship]]