|
S3TC
S3 Texture Compression (S3TC) (sometimes also called DXTn, DXTC, or BCn) is a group of related lossy texture compression algorithms originally developed by Iourcha et al. of S3 Graphics, Ltd. for use in their Savage 3D computer graphics accelerator. The method of compression is strikingly similar to the previously published Color Cell Compression, which is in turn an adaptation of Block Truncation Coding published in the late 1970s. Unlike some image compression algorithms (e.g. JPEG), S3TC's fixed-rate data compression coupled with the single memory access (cf. Color Cell Compression and some VQ-based schemes) made it well-suited for use in compressing textures in hardware-accelerated 3D computer graphics. Its subsequent inclusion in Microsoft's DirectX 6.0 and OpenGL 1.3 (via the GL_EXT_texture_compression_s3tc extension) led to widespread adoption of the technology among hardware and software makers. While S3 Graphics is no longer a competitor in the graphics accelerator market ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Savage 3D
Savage was a product-line of PC graphics chipsets designed by S3. Graphics Processors Savage 3D At the 1998 E3 Expo S3 introduced the first Savage product, Savage3D. Compared to its ViRGE-derived predecessor (Trio3D), Savage3D was a technological leap forward. Its innovative feature-set included the following: * "free" (single-cycle) trilinear-filtering * hardware motion-compensation and subpicture alpha-blending ( MPEG-2 video) * integrated NTSC/PAL TV-encoder, (optional) Macrovision * S3 Texture Compression (S3TC) * multi-tap X/Y interpolating front-end (BITBLT) and back-end (overlay) video-scaler Unfortunately for S3, deliveries of the Savage3D were hampered by poor manufacturing yields. Only one major board-vendor, Hercules, made any real effort to ship a Savage3D product. S3's yield problems forced Hercules to hand pick usable chips from the silicon wafers. Combined with poor drivers and the chip's lack of multitexturing support, the Savage3D failed in the market. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Cell Compression
Color Cell Compression is a lossy image compression algorithm developed by Campbell et al., in 1986, which can be considered an early forerunner of modern texture compression algorithms, such as S3 Texture Compression and Adaptive Scalable Texture Compression. It is closely related to Block Truncation Coding, another lossy image compression algorithm, which predates Color Cell Compression, in that it uses the dominant luminance of a block of pixels to partition said pixels into two representative colors. The primary difference between Block Truncation Coding and Color Cell Compression is that the former was designed to compress grayscale images and the latter was designed to compress color images. Also, Block Truncation Coding requires that the standard deviation of the colors of pixels in a block be computed in order to compress an image, whereas Color Cell Compression does not use the standard deviation. Both algorithms, though, can compress an image down to effectively 2 bit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lossy Compression
In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size for storing, handling, and transmitting content. The different versions of the photo of the cat on this page show how higher degrees of approximation create coarser images as more details are removed. This is opposed to lossless data compression (reversible data compression) which does not degrade the data. The amount of data reduction possible using lossy compression is much higher than using lossless techniques. Well-designed lossy compression technology often reduces file sizes significantly before degradation is noticed by the end-user. Even when noticeable by the user, further data reduction may be desirable (e.g., for real-time communication or to reduce transmission times or storage needs). The most widely used lossy compression al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lossy Data Compression
In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size for storing, handling, and transmitting content. The different versions of the photo of the cat on this page show how higher degrees of approximation create coarser images as more details are removed. This is opposed to Lossless compression, lossless data compression (reversible data compression) which does not degrade the data. The amount of data reduction possible using lossy compression is much higher than using lossless techniques. Well-designed lossy compression technology often reduces file sizes significantly before degradation is noticed by the end-user. Even when noticeable by the user, further data reduction may be desirable (e.g., for real-time communication or to reduce transmission times or storage needs). The most widely use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Texture Compression
Texture compression is a specialized form of image compression designed for storing texture maps in 3D computer graphics rendering systems. Unlike conventional image compression algorithms, texture compression algorithms are optimized for random access. Tradeoffs In their seminal paper on texture compression, Beers, Agrawala and Chaddha list four features that tend to differentiate texture compression from other image compression techniques. These features are: ;Decoding Speed: It is highly desirable to be able to render directly from the compressed texture data and so, in order not to impact rendering performance, decompression must be fast. ;Random Access: Since predicting the order that a renderer accesses texels would be difficult, any texture compression scheme must allow fast random access to decompressed texture data. This tends to rule out many better-known image compression schemes such as JPEG or run-length encoding. ;Compression Rate and Visual Quality: In a rendering ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S3 Graphics
S3 Graphics, Ltd (commonly referred to as S3) was an American computer graphics company. The company sold the Trio, ViRGE, Savage 3D, and Chrome series of graphics processors. Struggling against competition from 3dfx Interactive, ATI and Nvidia, it merged with hardware manufacturer Diamond Multimedia in 1999. The resulting company renamed itself to SONICblue Incorporated, and, two years later, the graphics portion was spun off into a new joint effort with VIA Technologies. The new company focused on the mobile graphics market. VIA Technologies' stake in S3 Graphics was purchased by HTC in 2011. History S3 was founded and incorporated in January 1989 by Dado Banatao and Ronald Yara. It was named S3 as it was Banatao's third startup company. The company's first products were among the earliest graphical user interface (GUI) accelerators. These chips were popular with video card manufacturers, and their followup designs, including the Trio64, made strong inroads with OEMs. S ... [...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] |
Doom 3
''Doom 3'' is a 2004 survival horror first-person shooter video game developed by id Software and published by Activision. ''Doom 3'' was originally released for Microsoft Windows on August 3, 2004, adapted for Linux later that year, and ported by Aspyr Media for Mac OS X in 2005. Developer Vicarious Visions ported the game to the Xbox, releasing it on April 3, 2005. ''Doom 3'' is set on Mars in 2145, where a military-industrial conglomerate has set up a scientific research facility into fields such as teleportation, biological research, and advanced weapons design. The teleportation experiments open a gateway to Hell, resulting in a catastrophic invasion of the Mars base by demons. The player controls a space marine who fights through the base to stop the demons attacking Mars and reaching Earth. ''Doom 3'' is the first reboot of the ''Doom'' series, ignoring the events of the previous games. ''Doom 3'' utilizes the id Tech 4 game engine, which has since been licensed out to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FourCC
A FourCC ("four-character code") is a sequence of four bytes (typically ASCII) used to uniquely identify data formats. It originated from the OSType or ResType metadata system used in classic Mac OS and was adopted for the Amiga/Electronic Arts Interchange File Format and derivatives. The idea was later reused to identify compressed data types in QuickTime and DirectShow. History In 1984, the earliest version of a Macintosh OS, Apple System 1, was released. It used the single-level Macintosh File System with metadata fields including file types, creator (application) information, and forks to store additional resources. All these fields are four-character codes known as OSType. It was possible to change this information without changing the data itself, so that they could be interpreted differently. Identical codes were used throughout the system, as type tags for all kinds of data. In 1985, Electronic Arts introduced the Interchange File Format (IFF) meta-format (family of f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ATI Technologies
ATI Technologies Inc. (commonly called ATI) was a Canadian semiconductor industry, semiconductor technology corporation based in Markham, Ontario, Markham, Ontario, that specialized in the development of graphics processing units and chipsets. Founded in 1985 as Array Technology Inc., the company listed publicly in 1993. Advanced Micro Devices (AMD) acquired ATI in 2006. As a major fabrication-less or fabless semiconductor company, ATI conducted research and development in-house and outsourcing, outsourced the manufacturing and assembly of its products. With the decline and eventual bankruptcy of 3dfx in 2000, ATI and its chief rival Nvidia emerged as the two dominant players in the graphics processors industry, eventually forcing other manufacturers into niche roles. The acquisition of ATI in 2006 was important to AMD's strategic development of its AMD Fusion, Fusion generation of computer processors, which integrated general processing abilities with graphics processing function ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compression Artifacts
A compression artifact (or artefact) is a noticeable distortion of media (including images, audio, and video) caused by the application of lossy compression. Lossy data compression involves discarding some of the media's data so that it becomes small enough to be stored within the desired disk space or transmitted (''streamed'') within the available bandwidth (known as the data rate or bit rate). If the compressor cannot store enough data in the compressed version, the result is a loss of quality, or introduction of artifacts. The compression algorithm may not be intelligent enough to discriminate between distortions of little subjective importance and those objectionable to the user. The most common digital compression artifacts are DCT blocks, caused by the discrete cosine transform (DCT) compression algorithm used in many digital media standards, such as JPEG, MP3, and MPEG video file formats. These compression artifacts appear when heavy compression is applied, and occu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Normal Mapping
In 3D computer graphics, normal mapping, or Dot3 bump mapping, is a texture mapping technique used for faking the lighting of bumps and dents – an implementation of bump mapping. It is used to add details without using more polygons. A common use of this technique is to greatly enhance the appearance and details of a low polygon model by generating a normal map from a high polygon model or height map. Normal maps are commonly stored as regular RGB images where the RGB components correspond to the X, Y, and Z coordinates, respectively, of the surface normal. History In 1978 Jim Blinn described how the normals of a surface could be perturbed to make geometrically flat faces have a detailed appearance. The idea of taking geometric details from a high polygon model was introduced in "Fitting Smooth Surfaces to Dense Polygon Meshes" by Krishnamurthy and Levoy, Proc. SIGGRAPH 1996, where this approach was used for creating displacement maps over nurbs. In 1998, two papers were pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Pixel Shader")
