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GIF89a
The Graphics Interchange Format (GIF; or , see pronunciation) is a bitmap image format that was developed by a team at the online services provider CompuServe led by American computer scientist Steve Wilhite and released on 15 June 1987. It is in widespread usage on the World Wide Web due to its wide support and portability between applications and operating systems. The format supports up to 8 bits per pixel for each image, allowing a single image to reference its own palette of up to 256 different colors chosen from the 24-bit RGB color space. It also supports animations and allows a separate palette of up to 256 colors for each frame. These palette limitations make GIF less suitable for reproducing color photographs and other images with color gradients, but well-suited for simpler images such as graphics or logos with solid areas of color. GIF images are compressed using the Lempel–Ziv–Welch (LZW) lossless data compression technique to reduce the file size witho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animated GIF
The Graphics Interchange Format (GIF; or , see pronunciation) is a bitmap In computing, a bitmap is a mapping from some domain (for example, a range of integers) to bits. It is also called a bit array or bitmap index. As a noun, the term "bitmap" is very often used to refer to a particular bitmapping application: t ... Image file formats, image format that was developed by a team at the online services provider CompuServe led by American computer scientist Steve Wilhite and released on 15 June 1987. It is in widespread usage on the World Wide Web due to its wide support and portability between applications and operating systems. The format supports up to 8-bit color, 8 bits per pixel for each image, allowing a single image to reference its own Palette (computing), palette of up to 256 different colors chosen from the 24-bit color, 24-bit RGB color model, RGB color space. It also supports animations and allows a separate palette of up to 256 colors for each frame. Thes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magic Number (programming)
In computer programming, a magic number is any of the following: * A unique value with unexplained meaning or multiple occurrences which could (preferably) be replaced with a named constant * A constant numerical or text value used to identify a file format or protocol; for files, see List of file signatures * A distinctive unique value that is unlikely to be mistaken for other meanings (e.g., Globally Unique Identifiers) Unnamed numerical constants The term ''magic number'' or ''magic constant'' refers to the anti-pattern of using numbers directly in source code. This has been referred to as breaking one of the oldest rules of programming, dating back to the COBOL, FORTRAN and PL/1 manuals of the 1960s. The use of unnamed magic numbers in code obscures the developers' intent in choosing that number, increases opportunities for subtle errors (e.g. is every digit correct in 3.14159265358979323846 and is this equal to 3.14159?) and makes it more difficult for the program to be a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lossless Data Compression
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 (and therefore reduced media sizes). By operation of the pigeonhole principle, no lossless compression algorithm can efficiently compress all possible data. For this reason, many different algorithms exist that are designed either with a specific type of input data in mind or with specific assumptions about what kinds of redundancy the uncompressed data are likely to contain. Therefore, compression ratios tend to be stronger on human- and machine-readable documents and code in comparison to entropic binary data (random bytes). Lossless data compression is used in many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portable Network Graphics
Portable Network Graphics (PNG, officially pronounced , colloquially pronounced ) is a raster-graphics file format that supports lossless data compression. PNG was developed as an improved, non-patented replacement for Graphics Interchange Format (GIF) — unofficially, the initials PNG stood for the recursive acronym "PNG's not GIF". PNG supports palette-based images (with palettes of 24-bit RGB or 32-bit RGBA colors), grayscale images (with or without an alpha channel for transparency), and full-color non-palette-based RGB or RGBA images. The PNG working group designed the format for transferring images on the Internet, not for professional-quality print graphics; therefore non-RGB color spaces such as CMYK are not supported. A PNG file contains a single image in an extensible structure of ''chunks'', encoding the basic pixels and other information such as textual comments and integrity checks documented in RFC 2083. PNG files use the file extension PNG or png and hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unisys
Unisys Corporation is an American multinational information technology (IT) services and consulting company headquartered in Blue Bell, Pennsylvania. It provides digital workplace solutions, cloud, applications, and infrastructure solutions, enterprise computing solutions, and business process solutions for organizations around the world. History Founding Unisys was formed in 1986 through the merger of mainframe corporations Sperry and Burroughs, with Burroughs buying Sperry for $4.8 billion. The name was chosen from over 31,000 submissions in an internal competition when Christian Machen submitted the word "Unisys" which was composed of parts of the words ''united'', ''information'' and ''systems''. The merger was the largest in the computer industry at the time and made Unisys the second largest computer company with annual revenue of $10.5 billion. Michael Blumenthal became CEO and Chairman. Soon after the merger, the market for proprietary mainframe-class systems—t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Netscape (web Browser)
The Netscape web browser is the general name for a series of web browsers formerly produced by Netscape, Netscape Communications Corporation, which eventually became a subsidiary of AOL. The original browser was once the dominant browser in terms of usage share, but as a result of the Browser wars#First Browser War, first browser war, it lost virtually all of its share to Internet Explorer due to Microsoft's anti-competitive bundelling of Internet Explorer with Windows. Netscape was discontinued and support for all Netscape browsers and client products was terminated on March 1, 2008. Timeline and history Netscape-based (versions 1.0–4.8) releases Netscape Navigator (versions 1.0–4.08) Netscape Navigator was the name of Netscape's web browser from versions 1.0 through 4.8. The first version of the browser was released in 1994, known as Mosaic and then Mosaic Netscape until a legal challenge from the National Center for Supercomputing Applications (makers of NCSA Mosaic, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
