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Fast Approximate Anti-aliasing
Fast approximate anti-aliasing (FXAA) is a screen-space anti-aliasing algorithm created by Timothy Lottes at Nvidia. FXAA 3 is released under a public domain license. A later version, FXAA 3.11, is released under a 3-clause BSD license. Algorithm description # The input data is the rendered image and optionally the luminance data. # Acquire the luminance data. This data could be passed into the FXAA algorithm from the rendering step as an alpha channel embedded into the image to be antialiased, calculated from the rendered image, or approximated by using the green channel as the luminance data. # Find high contrast pixels by using a high pass filter that uses the luminance data. Low contrast pixels that are found are excluded from being further altered by FXAA. The high pass filter that excludes low contrast pixels can be tuned to balance speed and sensitivity. # Use contrast between adjacent pixels to heuristically find edges, and determine whether the edges are in the horizo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Screen-space
This is a glossary of terms relating to computer graphics. For more general computer hardware terms, see glossary of computer hardware terms. 0–9 A B C D E F G H I K L M N O P Q R S T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Blend
In computer graphics, alpha compositing or alpha blending is the process of combining one image with a background to create the appearance of partial or full transparency. It is often useful to render picture elements (pixels) in separate passes or layers and then combine the resulting 2D images into a single, final image called the composite. Compositing is used extensively in film when combining computer-rendered image elements with live footage. Alpha blending is also used in 2D computer graphics to put rasterized foreground elements over a background. In order to combine the picture elements of the images correctly, it is necessary to keep an associated ''matte'' for each element in addition to its color. This matte layer contains the coverage information—the shape of the geometry being drawn—making it possible to distinguish between parts of the image where something was drawn and parts that are empty. Although the most basic operation of combining two images is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temporal Anti-aliasing
Temporal anti-aliasing (TAA) 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 pixel. Pixels sampled in past frames are blended with pixels sampled in the current frame to produce an anti-aliased image.Brian Kari, Epic Game"High Quality Temporal Supersampling" TAA compared to MSAA Prior to the development of TAA, MSAA was the dominant anti-aliasing technique. MSAA samples (renders) each pixel multiple times at different locations within the frame and averages the samples to produce the final pixel value. In contrast, TAA samples each pixel only once per frame, but it samples the pixels at a different locations in different frames. This makes TAA faster than MSAA. In parts of the picture without motion, TAA effectively computes MSAA over multiple frames ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anisotropic Filtering
In 3D computer graphics, anisotropic filtering (abbreviated AF) is a method of enhancing the image quality of textures on surfaces of computer graphics that are at oblique viewing angles with respect to the camera where the projection of the texture (not the polygon or other primitive on which it is rendered) appears to be non-orthogonal (thus the origin of the word: "an" for ''not'', "iso" for ''same'', and "tropic" from tropism, relating to direction; anisotropic filtering does not filter the same in every direction). Like bilinear and trilinear filtering, anisotropic filtering eliminates aliasing effects, but improves on these other techniques by reducing blur and preserving detail at extreme viewing angles. Anisotropic filtering is relatively intensive (primarily memory bandwidth and to some degree computationally, though the standard space–time tradeoff rules apply) and only became a standard feature of consumer-level graphics cards in the late 1990s. Anisotropic filt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multisample Anti-aliasing
Multisample anti-aliasing (MSAA) is a type of spatial anti-aliasing, a technique used in computer graphics to remove jaggies. Definition The term generally refers to a special case of supersampling. Initial implementations of full-scene anti-aliasing ( FSAA) worked conceptually by simply rendering a scene at a higher resolution, and then downsampling to a lower-resolution output. Most modern GPUs are capable of this form of anti-aliasing, but it greatly taxes resources such as texture, bandwidth, and fillrate. (If a program is highly TCL-bound or CPU-bound, supersampling can be used without much performance hit.) According to the OpenGL GL_ARB_multisample specification, "multisampling" refers to a specific optimization of supersampling. The specification dictates that the renderer evaluate the fragment program once per pixel, and only "truly" supersample the depth and stencil values. (This is not the same as supersampling but, by the OpenGL 1.5 specification, the definition ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphological Antialiasing
Morphological antialiasing (MLAA) is a technique for minimizing the distortion artifacts known as aliasing when representing a high-resolution image at a lower resolution. Contrary to multisample anti-aliasing (MSAA), which does not work for deferred rendering, MLAA is a post-process filtering which detects borders in the resulting image and then finds specific patterns in these. Anti-aliasing is achieved by blending pixels in these borders, according to the pattern they belong to and their position within the pattern. Enhanced subpixel morphological antialiasing, or SMAA, is an image-based GPU-based implementation of MLAA developed by Universidad de Zaragoza and Crytek. See also * Fast approximate anti-aliasing * Multisample anti-aliasing * Anisotropic filtering * Temporal anti-aliasing * Spatial anti-aliasing In digital signal processing, spatial anti-aliasing is a technique for minimizing the distortion artifacts (aliasing) when representing a high-resolution image at a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heads-up Display (video Games)
In video gaming, the HUD (heads-up display) or status bar is the method by which information is visually relayed to the player as part of a game's user interface. It takes its name from the head-up displays used in modern aircraft. The HUD is frequently used to simultaneously display several pieces of information including the main character's health, items, and an indication of game progression (such as score or level). Shown on the HUD While the information that is displayed on the HUD depends greatly on the game, there are many features that players recognize across many games. Most of them are static onscreen so that they stay visible during gameplay. Common features include: * Health/lives – this might include the player's character and possibly other important characters, such as allies or bosses. Real-time strategy games usually show the health of every unit visible on screen. Also, in many (but not all) first- and third-person shooters, when the player is damaged ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Texture Mapping
Texture mapping is a method for mapping a texture on a computer-generated graphic. Texture here can be high frequency detail, surface texture, or color. History The original technique was pioneered by Edwin Catmull in 1974. Texture mapping originally referred to diffuse mapping, a method that simply mapped pixels from a texture to a 3D surface ("wrapping" the image around the object). In recent decades, the advent of multi-pass rendering, multitexturing, mipmaps, and more complex mappings such as height mapping, bump mapping, normal mapping, displacement mapping, reflection mapping, specular mapping, occlusion mapping, and many other variations on the technique (controlled by a materials system) have made it possible to simulate near-photorealism in real time by vastly reducing the number of polygons and lighting calculations needed to construct a realistic and functional 3D scene. Texture maps A is an image applied (mapped) to the surface of a shape or polygon. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multisample Anti-aliasing
Multisample anti-aliasing (MSAA) is a type of spatial anti-aliasing, a technique used in computer graphics to remove jaggies. Definition The term generally refers to a special case of supersampling. Initial implementations of full-scene anti-aliasing ( FSAA) worked conceptually by simply rendering a scene at a higher resolution, and then downsampling to a lower-resolution output. Most modern GPUs are capable of this form of anti-aliasing, but it greatly taxes resources such as texture, bandwidth, and fillrate. (If a program is highly TCL-bound or CPU-bound, supersampling can be used without much performance hit.) According to the OpenGL GL_ARB_multisample specification, "multisampling" refers to a specific optimization of supersampling. The specification dictates that the renderer evaluate the fragment program once per pixel, and only "truly" supersample the depth and stencil values. (This is not the same as supersampling but, by the OpenGL 1.5 specification, the definition ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pixel Shader
In computer graphics, a shader is a computer program that calculates the appropriate levels of light, darkness, and color during the rendering of a 3D scene - a process known as ''shading''. Shaders have evolved to perform a variety of specialized functions in computer graphics special effects and video post-processing, as well as general-purpose computing on graphics processing units. Traditional shaders calculate rendering effects on graphics hardware with a high degree of flexibility. Most shaders are coded for (and run on) a graphics processing unit (GPU), though this is not a strict requirement. ''Shading languages'' are used to program the GPU's rendering pipeline, which has mostly superseded the fixed-function pipeline of the past that only allowed for common geometry transforming and pixel-shading functions; with shaders, customized effects can be used. The position and color (hue, saturation, brightness, and contrast) of all pixels, vertices, and/or textures us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edge Detection
Edge detection includes a variety of mathematical methods that aim at identifying edges, curves in a digital image at which the image brightness changes sharply or, more formally, has discontinuities. The same problem of finding discontinuities in one-dimensional signals is known as ''step detection'' and the problem of finding signal discontinuities over time is known as ''change detection''. Edge detection is a fundamental tool in image processing, machine vision and computer vision, particularly in the areas of feature detection and feature extraction. Motivations The purpose of detecting sharp changes in image brightness is to capture important events and changes in properties of the world. It can be shown that under rather general assumptions for an image formation model, discontinuities in image brightness are likely to correspond to: * discontinuities in depth, * discontinuities in surface orientation, * changes in material properties and * variations in scene illumi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spatial Anti-aliasing
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. Anti-aliasing means removing signal components that have a higher frequency than is able to be properly resolved by the recording (or sampling) device. This removal is done before (re)sampling at a lower resolution. When sampling is performed without removing this part of the signal, it causes undesirable artifacts such as black-and-white noise. In signal acquisition and audio, anti-aliasing is often done using an analog anti-aliasing filter to remove the out-of-band component of the input signal prior to sampling with an analog-to-digital converter. In digital photography, optical anti-aliasing filters made of birefringent materials smooth the signal in the spatial optical domain. The anti-a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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