Pixelization

Pixelization (British English, pixelisation) 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 resolution. It is primarily used for censorship. The effect is a standard graphics filter, available in all but the most basic bitmap graphics editors.

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, as in the television series COPS. Bystanders and others who do not sign release forms are also customarily pixelized. Footage of nudity (including genitals, buttocks, nipples or areolae) is likewise obscured in some media: before the watershed in many countries, in newspapers or general magazines, 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) may also be censored in this manner. Pixelization is not usually used for this purpose in films, DVDs, subscription television services, or pornography (except for countries in which the law requires it). When obscene language is censored by an audible bleep, the mouth of the speaker may be pixelized to prevent lip reading, often as in COPS graphic injuries and excess blood will be pixelized.

Pixelization may also be used to avoid unintentional product placement, or to hide elements that would date a broadcast, such as date and time stamps on home video submissions. Censorship for such purposes is most common on reality television series.

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