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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 resolution. It is primarily used for censorship. The effect is a standard graphics filter, available in all but the most basic bitmap graphics editors.
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. [1] [2] 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.
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; [3] 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. [4] Other visual processing techniques can help reduce the shocking aspect of images or videos while preserving most of the information of the media. [4] [5]
Nudity is obscured on broadcast television stations 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. [6] 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. [7] In Thailand, restrictions are placed on television broadcast depiction of cigarettes being smoked, [8] alcohol being consumed, or guns being pointed at people. Pixelization is one method of censoring this content.
Rendering is the process of generating a photorealistic or non-photorealistic image from input data such as 3D models. The word "rendering" originally meant the task performed by an artist when depicting a real or imaginary thing. Today, to "render" commonly means to generate an image or video from a precise description using a computer program.
Jaggies are artifacts in raster images, most frequently from aliasing, which in turn is often caused by non-linear mixing effects producing high-frequency components, or missing or poor anti-aliasing filtering prior to sampling.
Lossless compression is a class of data compression that allows the original data to be perfectly reconstructed from the compressed data with no loss of information. Lossless compression is possible because most real-world data exhibits statistical redundancy. By contrast, lossy compression permits reconstruction only of an approximation of the original data, though usually with greatly improved compression rates.
In digital imaging, a pixel, pel, or picture element is the smallest addressable element in a raster image, or the smallest addressable element in a dot matrix display device. In most digital display devices, pixels are the smallest element that can be manipulated through software.
The painter's algorithm is an algorithm for visible surface determination in 3D computer graphics that works on a polygon-by-polygon basis rather than a pixel-by-pixel, row by row, or area by area basis of other Hidden-Surface Removal algorithms. The painter's algorithm creates images by sorting the polygons within the image by their depth and placing each polygon in order from the farthest to the closest object.
Video Graphics Array (VGA) is a video display controller and accompanying de facto graphics standard, first introduced with the IBM PS/2 line of computers in 1987, which became ubiquitous in the IBM PC compatible industry within three years. The term can now refer to the computer display standard, the 15-pin D-subminiature VGA connector, or the 640 × 480 resolution characteristic of the VGA hardware.
In digital signal processing, spatial anti-aliasing is a technique for minimizing the distortion artifacts (aliasing) when representing a high-resolution image at a lower resolution. Anti-aliasing is used in digital photography, computer graphics, digital audio, and many other applications.
In Japan, pornography has unique characteristics that readily distinguish it from western pornography. Pornographic films are known as "adult videos" (AV) in Japan, so Japanese adult videos (JAV) refers to the Japanese Adult Video industry. Animated films are referred to as hentai in English, but in Japan the terms "adult anime" and "erotic animation" are used. In addition to pornographic videos and magazines featuring live actors, there are now categories of pornographic manga and anime, and pornographic computer games.
Mode 13h is the standard 256-color mode on VGA graphics hardware introduced in 1987 with the IBM PS/2. It has a resolution of 320 × 200 pixels. It was used in computer games and art/animation software of the late 1980s and early to mid-1990s. "13h" refers to the number of the mode in the VGA BIOS. The "h" stands for hexadecimal.
The Color Graphics Adapter (CGA), originally also called the Color/Graphics Adapter or IBM Color/Graphics Monitor Adapter, introduced in 1981, was IBM's first color graphics card for the IBM PC and established a de facto computer display standard.
A bleep censor is the replacement of profanity and classified information with a beep sound, used in public television, radio and social media.
Pixel art is a form of digital art drawn with graphical software where images are built using pixels as the only building block. It is widely associated with the low-resolution graphics from 8-bit and 16-bit era computers, arcade machines and video game consoles, in addition to other limited systems such as LED displays and graphing calculators, which have a limited number of pixels and colors available. The art form is still employed to this day by pixel artists and game studios, even though the technological limitations have since been surpassed.
The display resolution or display modes of a digital television, computer monitor, or other display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by different factors in cathode-ray tube (CRT) displays, flat-panel displays and projection displays using fixed picture-element (pixel) arrays.
Dither is an intentionally applied form of noise used to randomize quantization error, preventing large-scale patterns such as color banding in images. Dither is routinely used in processing of both digital audio and video data, and is often one of the last stages of mastering audio to a CD.
In computer graphics, pixelation is caused by displaying a bitmap or a section of a bitmap at such a large size that individual pixels, small single-colored square display elements that comprise the bitmap, are visible. Such an image is said to be pixelated.
Seam carving is an algorithm for content-aware image resizing, developed by Shai Avidan, of Mitsubishi Electric Research Laboratories (MERL), and Ariel Shamir, of the Interdisciplinary Center and MERL. It functions by establishing a number of seams in an image and automatically removes seams to reduce image size or inserts seams to extend it. Seam carving also allows manually defining areas in which pixels may not be modified, and features the ability to remove whole objects from photographs.
Fogging, also known as blurring, is used for censorship or privacy. A visual area of a picture or movie is blurred to obscure it from sight. This form of censorship is used for sexually related images/scenes, hiding genitals, pubic hair, buttocks, female nipples/breasts, or sexual activity of any sort. Pixelization is a form of fogging. In Japan, where it is called bokashi, fogging is employed on most films aired on public television that feature adult content of any kind.
Censorship in New Zealand has been present since around 1850 and is currently managed by the Classification Office under the Films, Videos, and Publications Classification Act 1993.
In computing, 3D interaction is a form of human-machine interaction where users are able to move and perform interaction in 3D space. Both human and machine process information where the physical position of elements in the 3D space is relevant.
An obscenity is any utterance or act that strongly offends the prevalent morality of the time. It is derived from the Latin obscēnus, obscaenus, "boding ill; disgusting; indecent", of uncertain etymology. Generally, the term can be used to indicate strong moral repugnance and outrage in expressions such as "obscene profits" and "the obscenity of war". As a legal term, it usually refers to descriptions and depictions of people engaged in sexual and excretory activity.
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