Pixelization is a video- and image-editing technique in which an image is blurred by displaying part or all of it at a markedly lower resolution. It is primarily used for censorship
thumb|[[Book burning]] following the [[1973 Chilean coup d'état|1973 coup]] that installed the [[Military government of Chile |Pinochet regime]] in Chile...

. The effect is a standard graphics filter, available in all but the most basic bitmap graphics editor
Raster graphics editor
A raster graphics editor is a computer program that allows users to paint and edit pictures interactively on the computer screen and save them in one of many popular “bitmap” or “raster” formats such as JPEG, PNG, GIF and TIFF....


Pixelization as censorship

A familiar example of pixelization can be found in television news and documentary productions, in which vehicle license plates and faces of suspects at crime scenes are routinely obscured to maintain the presumption of innocence
Presumption of innocence
The presumption of innocence, sometimes referred to by the Latin expression Ei incumbit probatio qui dicit, non qui negat, is the principle that one is considered innocent until proven guilty. Application of this principle is a legal right of the accused in a criminal trial, recognised in many...

, as in the television series COPS
COPS (TV series)
Cops is an American documentary/reality television series that follows police officers, constables, and sheriff's deputies during patrols and other police activities...

. Bystanders and others who do not sign release forms are also customarily pixelized. Footage of nudity (including genitalia, buttocks, or breasts) is likewise obscured in some media: before the watershed
Watershed (television)
In television, the term watershed denotes the time period in a television schedule during which programs with adult content can air....

 in many countries, in newspapers or general magazine
Magazines, periodicals, glossies or serials are publications, generally published on a regular schedule, containing a variety of articles. They are generally financed by advertising, by a purchase price, by pre-paid magazine subscriptions, or all three...

s, or in places in which the public cannot avoid seeing the image (such as on billboards). Drug references, as well as gestures considered obscene (such as the finger
Finger (gesture)
In Western culture, the finger , also known as the middle finger, is an obscene hand gesture, often meaning the phrases "fuck off" , "fuck you" or "up yours"...

) may also be censored in this manner. Pixelization is not usually used for this purpose in films, DVDs, subscription television services, pornography
Pornography or porn is the explicit portrayal of sexual subject matter for the purposes of sexual arousal and erotic satisfaction.Pornography may use any of a variety of media, ranging from books, magazines, postcards, photos, sculpture, drawing, painting, animation, sound recording, film, video,...

 (except for countries in which the law requires it). When obscene language is censored by an audible bleep
Bleep censor
A bleep censor is the replacement of profanity or classified information with a beep sound , in television or radio...

, the mouth of the speaker may be pixelized to prevent lip reading
Lip reading
Lip reading, also known as lipreading or speechreading, is a technique of understanding speech by visually interpreting the movements of the lips, face and tongue with information provided by the context, language, and any residual hearing....

, often as in COPS
COPS (TV series)
Cops is an American documentary/reality television series that follows police officers, constables, and sheriff's deputies during patrols and other police activities...

graphic injuries and excess blood will be pixelized.

Pixelization may also be used to avoid unintentional product placement
Product placement
Product placement, or embedded marketing, is a form of advertisement, where branded goods or services are placed in a context usually devoid of ads, such as movies, music videos, the story line of television shows, or news programs. The product placement is often not disclosed at the time that the...

, or to hide elements that would date a broadcast, such as date
A calendar is a system of organizing days for social, religious, commercial, or administrative purposes. This is done by giving names to periods of time, typically days, weeks, months, and years. The name given to each day is known as a date. Periods in a calendar are usually, though not...

 and time stamps on home video
Home video
Home video is a blanket term used for pre-recorded media that is either sold or rented/hired for home cinema entertainment. The term originates from the VHS/Betamax era but has carried over into current optical disc formats like DVD and Blu-ray Disc and, to a lesser extent, into methods of digital...

 submissions. Censorship for such purposes is most common on reality television
Reality television
Reality television is a genre of television programming that presents purportedly unscripted dramatic or humorous situations, documents actual events, and usually features ordinary people instead of professional actors, sometimes in a contest or other situation where a prize is awarded...


Pixelization in media

Pixelization has also been used for artistic effect, notably in the art print The Wave of the Future, a reinterpretation of Katsushika Hokusai's
was a Japanese artist, ukiyo-e painter and printmaker of the Edo period. He was influenced by such painters as Sesshu, and other styles of Chinese painting...

 The Great Wave at Kanagawa. In this updated print, the image of the large ocean wave shifts from the traditional style of the Japanese woodcut
Woodcut—occasionally known as xylography—is a relief printing artistic technique in printmaking in which an image is carved into the surface of a block of wood, with the printing parts remaining level with the surface while the non-printing parts are removed, typically with gouges...

 print to a pixelized image and finally to a wireframe model computer graphics
Computer graphics
Computer graphics are graphics created using computers and, more generally, the representation and manipulation of image data by a computer with help from specialized software and hardware....

 image. Westworld
Westworld is a 1973 science fiction-thriller film written and directed by novelist Michael Crichton and produced by Paul Lazarus III. It stars Yul Brynner as a lifelike robot in a futuristic Western-themed amusement park, and Richard Benjamin and James Brolin as guests of the park.Westworld was the...

(1973) was the first feature film to use digital image processing
Digital image processing
Digital image processing is the use of computer algorithms to perform image processing on digital images. As a subcategory or field of digital signal processing, digital image processing has many advantages over analog image processing...

 to pixelize photography to simulate an android's point of view.

Alternative techniques

For many censorship purposes, pixelization has been supplanted by blurring the image, or black rectangular or square boxes (known as censor bars) may be used to cover parts of images completely (for example, a black box inserted over the eyes rather than pixelization of the entire face).

A drawback of pixelization is that any differences between the large pixels can be exploited in moving images to reconstruct the original, unpixelized image; 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.

International legal standards

Nudity is the state of wearing no clothing. The wearing of clothing is exclusively a human characteristic. The amount of clothing worn depends on functional considerations and social considerations...

 is obscured on network television in the United States. Japanese pornography
Pornography in Japan
Pornography in Japan.-Before the 20th century:Shunga or pornographic wood-block pictures were printed with all imaginable situations. These often took the form of a book with sentences to describe verbal utterances of the partners, as well as to offer brief descriptions of a scene...

 laws require that genitals in films (including animated works) be obscured. In Thailand, restrictions are placed on television broadcast depiction of cigarettes being smoked, alcohol being consumed, or guns being pointed at people. Pixelization is the most common method of censoring this content.

See also

  • Bleep censor
    Bleep censor
    A bleep censor is the replacement of profanity or classified information with a beep sound , in television or radio...

  • Reverse video
    Reverse video
    Reverse video is a computer display technique whereby the background and text colour values are inverted. On older computers, displays were usually configured to display white text on a black background by default. For emphasis, one swapped the color scheme to bright background with dark text...

  • Tape delay (broadcasting)
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