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Anti-aliasing Algorithms
Anti-aliasing may refer to any of a number of techniques to combat the problems of aliasing in a sampled signal such as a digital image or digital audio recording. Specific topics in anti-aliasing include: * Anti-aliasing filter, a filter used before a signal sampler to restrict the bandwidth of a signal such as in audio applications. * Manual anti-aliasing, an artistic technique done in pixel art graphics to smooth transitions between shapes, soften lines or blur edges. * Computer-generated imagery (CGI), the application of computer graphics for creating or improving images in art, printed media, simulators, videos and video games. * Spatial anti-aliasing, the technique of minimizing aliasing when representing a high-resolution image at a lower resolution ** Fast approximate anti-aliasing (FXAA), an anti-aliasing algorithm created by Timothy Lottes under Nvidia. May also be referred to as Fast Sample Anti-aliasing (FSAA). ** Multisample anti-aliasing (MSAA), a type of spatial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aliasing
In signal processing and related disciplines, aliasing is a phenomenon that a reconstructed signal from samples of the original signal contains low frequency components that are not present in the original one. This is caused when, in the original signal, there are components at frequency exceeding a certain frequency called Nyquist frequency, f_s / 2, where f_s is the sampling frequency ( undersampling). This is because typical reconstruction methods use low frequency components while there are a number of frequency components, called aliases, which sampling result in the identical sample. It also often refers to the distortion or artifact that results when a signal reconstructed from samples is different from the original continuous signal. Aliasing can occur in signals sampled in time, for instance in digital audio or the stroboscopic effect, and is referred to as temporal aliasing. Aliasing in spatially sampled signals (e.g., moiré patterns in digital images) is referre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temporal Anti-aliasing
Temporal anti-aliasing (TAA), also known as TXAA (a proprietary technology) or TMAA/TSSAA (''Temporal Super-Sampling Anti-Aliasing''), is a spatial anti-aliasing technique for computer-generated video that combines information from past frames and the current frame to remove jaggies in the current frame. In TAA, each pixel is sampled once per frame but in each frame the sample is at a different location within the frame. Pixels sampled in past frames are blended with pixels sampled in the current frame to produce an anti-aliased image. Although this method makes TAA achieve a result comparable to supersampling, the technique inevitably causes Ghosting (television), ghosting and blurriness to the image. TAA compared to MSAA Prior to the development of TAA, Multisample anti-aliasing, MSAA was the dominant anti-aliasing technique. MSAA samples (renders) only the edges of polygons, then averages the samples to produce the final pixel value, making it surprisingly efficient in GPU-bound ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pixel-art Scaling Algorithms
Pixel art scaling algorithms are graphical filters that attempt to enhance the appearance of hand-drawn 2D pixel art graphics. These algorithms are a form of automatic image enhancement. Pixel art scaling algorithms employ methods significantly different than the common methods of image rescaling, which have the goal of preserving the appearance of images. As pixel art graphics are commonly used at very low resolutions, they employ careful coloring of individual pixels. This results in graphics that rely on a high amount of stylized visual cues to define complex shapes. Several specialized algorithms have been developed to handle re-scaling of such graphics. These specialized algorithms can improve the appearance of pixel-art graphics, but in doing so they introduce changes. Such changes may be undesirable, especially if the goal is to faithfully reproduce the original appearance. Since a typical application of this technology is improving the appearance of fourth-generation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aliasing
In signal processing and related disciplines, aliasing is a phenomenon that a reconstructed signal from samples of the original signal contains low frequency components that are not present in the original one. This is caused when, in the original signal, there are components at frequency exceeding a certain frequency called Nyquist frequency, f_s / 2, where f_s is the sampling frequency ( undersampling). This is because typical reconstruction methods use low frequency components while there are a number of frequency components, called aliases, which sampling result in the identical sample. It also often refers to the distortion or artifact that results when a signal reconstructed from samples is different from the original continuous signal. Aliasing can occur in signals sampled in time, for instance in digital audio or the stroboscopic effect, and is referred to as temporal aliasing. Aliasing in spatially sampled signals (e.g., moiré patterns in digital images) is referre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-aliasing Algorithms
Anti-aliasing may refer to any of a number of techniques to combat the problems of aliasing in a sampled signal such as a digital image or digital audio recording. Specific topics in anti-aliasing include: * Anti-aliasing filter, a filter used before a signal sampler to restrict the bandwidth of a signal such as in audio applications. * Manual anti-aliasing, an artistic technique done in pixel art graphics to smooth transitions between shapes, soften lines or blur edges. * Computer-generated imagery (CGI), the application of computer graphics for creating or improving images in art, printed media, simulators, videos and video games. * Spatial anti-aliasing, the technique of minimizing aliasing when representing a high-resolution image at a lower resolution ** Fast approximate anti-aliasing (FXAA), an anti-aliasing algorithm created by Timothy Lottes under Nvidia. May also be referred to as Fast Sample Anti-aliasing (FSAA). ** Multisample anti-aliasing (MSAA), a type of spatial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temporal Posterization
Posterization or posterisation of an image is the conversion of a continuous gradation of tone to several regions of fewer tones, causing abrupt changes from one tone to another. This was originally done with photographic processes to create posters. It can now be done photographically or with digital image processing, and may be deliberate or an unintended artifact of color quantization. Posterization is often the first step in vectorization (tracing) of an image. Cause The effect may be created deliberately, or happen accidentally. For artistic effect, most image editing programs provide a posterization feature, or photographic processes may be used. Unwanted posterization, also known as banding, may occur when the color depth, sometimes called bit depth, is insufficient to accurately sample a continuous gradation of color tone. As a result, a continuous gradient appears as a series of discrete steps or bands of color — hence the name. When discussing fixed pixel displ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exposure (photography)
In photography, exposure is the amount of light per unit area reaching a frame (photography), frame of photographic film or the surface of an electronic image sensor. It is determined by shutter speed, lens f-number, and scene luminance. Exposure is measured in unit of measurement, units of lux-seconds (symbol lxs), and can be computed from exposure value (EV) and scene luminance in a specified region. An "exposure" is a single shutter cycle. For example, a long-exposure photography, long exposure refers to a single, long shutter cycle to gather enough dim light, whereas a multiple exposure involves a series of shutter cycles, effectively layering a series of photographs in one image. The accumulated ''photometric exposure'' (''H''v) is the same so long as the total exposure time is the same. Definitions Radiant exposure Radiant exposure of a ''surface'', denoted ''H''e ("e" for "energetic", to avoid confusion with Photometry (optics), photometric quantities) and measured in , i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motion Blur
Motion blur is the apparent streaking of moving objects in a photograph or a sequence of frames, such as a film or animation. It results when the image being recorded changes during the recording of a single exposure, due to rapid movement or long-exposure photography, long exposure. Usages / Effects of motion blur Photography When a camera creates an image, that image does not represent a single instant of time. Because of technological constraints or artistic requirements, the image may represent the scene over a period of time. Most often this exposure time is brief enough that the image captured by the camera appears to capture an instantaneous moment, but this is not always so, and a fast moving object or a longer exposure time may result in blurring artifacts which make this apparent. As objects in a scene move, an image of that scene must represent an Integral, integration of all positions of those objects, as well as the camera's viewpoint, over the period of exposur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motion Lines
In comics and art more broadly, motion lines (also known as movement lines, action lines, speed lines, or zip ribbons) are the abstract lines that appear behind a moving object or person, parallel to its direction of movement, to make it appear as if it is moving quickly. They are common in Japanese manga and anime, of which ''Speed Racer'' is a classic example. Lines depicting wind and the trajectory of missiles appear in art as early as the 16th century. By the 19th century artists were drawing naturally occurring speed lines when showing the passage of an object through water or snow, but it was not until the 1870s that artists like Wilhelm Busch and Adolphe Willette began drawing motion lines to depict the movement of objects through air. The French artist Ernest Montaut is usually credited with the invention of ''speed lines''. He used the technique freely in his posters which were produced at a time when auto racing, speedboat racing and aircraft races were in their i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traditional Animation
Traditional animation (or classical animation, cel animation, or hand-drawn animation) is an animation technique in which each frame is drawing, drawn by hand. The technique was the dominant form of animation of the 20th century, until there was a shift to computer animation in the industry, such as Traditional animation#Modern process, digital ink and paint, a modern form of traditional animation methods, and 3D computer animation. Process Writing and storyboarding Animation production usually begins after a story is converted into an animation film script, from which a storyboard is derived. A storyboard has an appearance somewhat similar to comic book panels, and is a shot by shot breakdown of the staging, acting and any camera moves that will be present in the film. The images allow the animation team to plan the flow of the Plot (narrative), plot and the composition of the imagery. Storyboard artists will have regular meetings with the film director, director and may redra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wagon-wheel Effect
The wagon-wheel effect (alternatively called stagecoach-wheel effect) is an optical illusion in which a spoked wheel appears to rotate differently from its true rotation. The wheel can appear to rotate more slowly than the true rotation, it can appear stationary, or it can appear to rotate in the opposite direction from the true rotation (reverse rotation effect). The wagon-wheel effect is most often seen in film or television depictions of stagecoaches or wagons in Western movies, although recordings of any regularly spoked rotating object will show it, such as helicopter rotors, aircraft propellers and car rims. In these recorded media, the effect is a result of temporal aliasing. It can also commonly be seen when a rotating wheel is illuminated by flickering light. These forms of the effect are known as ''stroboscopic effects'': the original smooth rotation of the wheel is visible only intermittently. A version of the wagon-wheel effect can also be seen under continuous i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Graphics (publication)
''Computer Graphics'' was a publication of ACM SIGGRAPH ACM SIGGRAPH is the international Association for Computing Machinery's Special Interest Group on Computer Graphics and Interactive Techniques based in New York. It was founded in 1969 by Andy van Dam (its direct predecessor, ACM SICGRAPH was .... It served as its newsletter, and has published the yearly SIGGRAPH Conference Proceedings up to 2003, as well as a variety of papers on a quarterly basis. The last edition was published in 2011. External links Online archive Computer graphics organizations Association for Computing Machinery magazines Publications with year of establishment missing Magazines disestablished in 2011 Conference proceedings published in serials Newsletters Defunct computer magazines {{compu-mag-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
