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Number Nine Visual Technology
Number Nine Visual Technology Corporation was a manufacturer of video graphics chips and cards from 1982 to 1999. Number Nine developed the first 128-bit graphics processor (the Imagine 128), as well as the first 256-color (8-bit) and 16.8 million color (24-bit) cards. The name of the company, as well as many of its products (e.g., Revolution, Imagine, Pepper, Ticket to Ride) refer to Beatles songs. At system boot up, Number Nine cards' video BIOS splash screens display short phrases from Beatles songs related to the cards' model names. Card model names were usually preceded by a "#9" moniker. History Number Nine was founded in 1982 by Andrew Najda and Stan Bialek as Number Nine Computer Corporation. The company was renamed Number Nine Visual Technology Corporation in the early 1990s. For most of its existence, Number Nine was based in Lexington, Massachusetts. Number Nine initially made an Apple II accelerators, Apple II accelerator board, then later moved into the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wayback Machine
The Wayback Machine is a digital archive of the World Wide Web founded by the Internet Archive, a nonprofit based in San Francisco, California. Created in 1996 and launched to the public in 2001, it allows the user to go "back in time" and see how websites looked in the past. Its founders, Brewster Kahle and Bruce Gilliat, developed the Wayback Machine to provide "universal access to all knowledge" by preserving archived copies of defunct web pages. Launched on May 10, 1996, the Wayback Machine had more than 38.2 million records at the end of 2009. , the Wayback Machine had saved more than 760 billion web pages. More than 350 million web pages are added daily. History The Wayback Machine began archiving cached web pages in 1996. One of the earliest known pages was saved on May 10, 1996, at 2:08p.m. Internet Archive founders Brewster Kahle and Bruce Gilliat launched the Wayback Machine in San Francisco, California, in October 2001, primarily to address the problem of web co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VESA Local Bus
The VESA Local Bus (usually abbreviated to VL-Bus or VLB) is a short-lived expansion bus introduced during the i486 generation of x86 IBM-compatible personal computers. Created by VESA (Video Electronics Standards Association), the VESA Local Bus worked alongside the then-dominant ISA bus to provide a standardized high-speed conduit intended primarily to accelerate video (graphics) operations. VLB provides a standardized fast path that add-in (video) card makers could tap for greatly accelerated memory-mapped I/O and DMA, while still using the familiar ISA bus to handle basic device duties such as interrupts and port-mapped I/O. Some high-end 386dx motherboards also had a VL-Bus slot. Historical overview In the early 1990s, the I/O bandwidth of the prevailing ISA bus, 8.33 MB/s for standard 16 bit 8.33 MHz slots, had become a critical bottleneck to PC video and graphics performance. The need for faster graphics was driven by increased adoption of graphical user interfac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MPEG-1
MPEG-1 is a standard for lossy compression of video and audio. It is designed to compress VHS-quality raw digital video and CD audio down to about 1.5 Mbit/s (26:1 and 6:1 compression ratios respectively) without excessive quality loss, making video CDs, digital cable/satellite TV and digital audio broadcasting (DAB) practical. Today, MPEG-1 has become the most widely compatible lossy audio/video format in the world, and is used in a large number of products and technologies. Perhaps the best-known part of the MPEG-1 standard is the first version of the MP3 audio format it introduced. The MPEG-1 standard is published as ISO/IEC 11172 – Information technology—Coding of moving pictures and associated audio for digital storage media at up to about 1.5 Mbit/s. The standard consists of the following five ''Parts'': #Systems (storage and synchronization of video, audio, and other data together) #Video (compressed video content) #Audio (compressed audio content) #Conformance tes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specular Highlight
A specular highlight is the bright spot of light that appears on shiny objects when illuminated (for example, see image on right). Specular highlights are important in 3D computer graphics, as they provide a strong visual cue for the shape of an object and its location with respect to light sources in the scene. Microfacets The term ''specular'' means that light is perfectly reflected in a mirror-like way from the light source to the viewer. Specular reflection is visible only where the surface normal is oriented precisely halfway between the direction of incoming light and the direction of the viewer; this is called the half-angle direction because it bisects (divides into halves) the angle between the incoming light and the viewer. Thus, a specularly reflecting surface would show a specular highlight as the perfectly sharp reflected image of a light source. However, many shiny objects show blurred specular highlights. This can be explained by the existence of microfacets. W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distance Fog
Distance fog is a technique used in 3D computer graphics to enhance the perception of distance by shading distant objects differently. Because many of the shapes in graphical environments are relatively simple, and complex shadows are difficult to render, many graphics engines employ a "fog" gradient so objects further from the camera are progressively more obscured by haze and by aerial perspective. This technique simulates the effect of light scattering, which causes more distant objects to appear lower in contrast, especially in outdoor environments. Visibility in a natural haze declines exponentially, not linearly, with distance due to scattering. The colour of the light being scattered into the viewing path affects the colour of the haze; blue under blue skies, reddish near sunset, as with alpenglow. These more subtle details are represented in some graphics. "Fogging" is another use of distance fog in mid-to-late 1990s games, when processing power was not enough to r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Blending
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bilinear Filtering
In mathematics, bilinear interpolation is a method for interpolating functions of two variables (e.g., ''x'' and ''y'') using repeated linear interpolation. It is usually applied to functions sampled on a 2D rectilinear grid, though it can be generalized to functions defined on the vertices of (a mesh of) arbitrary convex quadrilaterals. Bilinear interpolation is performed using linear interpolation first in one direction, and then again in the other direction. Although each step is linear in the sampled values and in the position, the interpolation as a whole is not linear but rather quadratic in the sample location. Bilinear interpolation is one of the basic resampling techniques in computer vision and image processing, where it is also called bilinear filtering or bilinear texture mapping. Computation Suppose that we want to find the value of the unknown function ''f'' at the point (''x'', ''y''). It is assumed that we know the value of ''f'' at the four points ''Q''11 = ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Z-buffering
A depth buffer, also known as a z-buffer, is a type of data buffer used in computer graphics to represent depth information of objects in 3D space from a particular perspective. Depth buffers are an aid to rendering a scene to ensure that the correct polygons properly occlude other polygons. Z-buffering was first described in 1974 by Wolfgang Straßer in his PhD thesis on fast algorithms for rendering occluded objects. A similar solution to determining overlapping polygons is the painter's algorithm, which is capable of handling non-opaque scene elements, though at the cost of efficiency and incorrect results. In a 3D-rendering pipeline, when an object is projected on the screen, the depth (z-value) of a generated fragment in the projected screen image is compared to the value already stored in the buffer (depth test), and replaces it if the new value is closer. It works in tandem with the rasterizer, which computes the colored values. The fragment output by the rasterizer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gouraud Shading
Gouraud shading, named after Henri Gouraud, is an interpolation method used in computer graphics to produce continuous shading of surfaces represented by polygon meshes. In practice, Gouraud shading is most often used to achieve continuous lighting on triangle meshes by computing the lighting at the corners of each triangle and linearly interpolating the resulting colours for each pixel covered by the triangle. Gouraud first published the technique in 1971. Description Gouraud shading works as follows: An estimate to the surface normal of each vertex in a polygonal 3D model is either specified for each vertex or found by averaging the surface normals of the polygons that meet at each vertex. Using these estimates, lighting computations based on a reflection model, e.g. the Phong reflection model, are then performed to produce colour intensities at the vertices. For each screen pixel that is covered by the polygonal mesh, colour intensities can then be interpolated from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
