Pixelization
Pixelization 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 resolution. It is primarily used for censorship. The effect is a standard graphics filter, available in all but the most basic bitmap graphics editors.
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 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. Westworld 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
A black rectangular or square box may be used to occlude parts of images completely. 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; 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. Other visual processing techniques can help reduce the shocking aspect of images or videos while preserving most of the information of the media.