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Asymmetric Numeral Systems
Asymmetric numeral systems (ANS)J. Duda, K. Tahboub, N. J. Gadil, E. J. Delp''The use of asymmetric numeral systems as an accurate replacement for Huffman coding'' Picture Coding Symposium, 2015.J. Duda''Asymmetric numeral systems: entropy coding combining speed of Huffman coding with compression rate of arithmetic coding'' arXiv:1311.2540, 2013. is a family of entropy encoding methods introduced by Jarosław (Jarek) Duda from Jagiellonian University, used in data compression since 2014 due to improved performance compared to previous methods. ANS combines the compression ratio of arithmetic coding (which uses a nearly accurate probability distribution), with a processing cost similar to that of Huffman coding. In the tabled ANS (tANS) variant, this is achieved by constructing a finite-state machine to operate on a large alphabet without using multiplication. Among others, ANS is used in the Facebook Zstandard compressor [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entropy Encoding
In information theory, an entropy coding (or entropy encoding) is any lossless data compression method that attempts to approach the lower bound declared by Shannon's source coding theorem, which states that any lossless data compression method must have an expected code length greater than or equal to the entropy of the source. More precisely, the source coding theorem states that for any source distribution, the expected code length satisfies \operatorname E_ ell(d(x))\geq \operatorname E_ \log_b(P(x))/math>, where \ell is the function specifying the number of symbols in a code word, d is the coding function, b is the number of symbols used to make output codes and P is the probability of the source symbol. An entropy coding attempts to approach this lower bound. Two of the most common entropy coding techniques are Huffman coding and arithmetic coding. If the approximate entropy characteristics of a data stream are known in advance (especially for signal compression), a simple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple Inc
Apple Inc. is an American multinational corporation and technology company headquartered in Cupertino, California, in Silicon Valley. It is best known for its consumer electronics, software, and services. Founded in 1976 as Apple Computer Company by Steve Jobs, Steve Wozniak and Ronald Wayne, the company was incorporated by Jobs and Wozniak as Apple Computer, Inc. the following year. It was renamed Apple Inc. in 2007 as the company had expanded its focus from computers to consumer electronics. Apple is the largest technology company by revenue, with billion in the 2024 fiscal year. The company was founded to produce and market Wozniak's Apple I personal computer. Its second computer, the Apple II, became a best seller as one of the first mass-produced microcomputers. Apple introduced the Lisa in 1983 and the Macintosh in 1984, as some of the first computers to use a graphical user interface and a mouse. By 1985, internal company problems led to Jobs leavin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stirling's Approximation
In mathematics, Stirling's approximation (or Stirling's formula) is an asymptotic approximation for factorials. It is a good approximation, leading to accurate results even for small values of n. It is named after James Stirling, though a related but less precise result was first stated by Abraham de Moivre. One way of stating the approximation involves the logarithm of the factorial: \ln(n!) = n\ln n - n +O(\ln n), where the big O notation means that, for all sufficiently large values of n, the difference between \ln(n!) and n\ln n-n will be at most proportional to the logarithm of n. In computer science applications such as the worst-case lower bound for comparison sorting, it is convenient to instead use the binary logarithm, giving the equivalent form \log_2 (n!) = n\log_2 n - n\log_2 e +O(\log_2 n). The error term in either base can be expressed more precisely as \tfrac12\log(2\pi n)+O(\tfrac1n), corresponding to an approximate formula for the factorial itself, n! \sim \sqr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combinations
In mathematics, a combination is a selection of items from a set that has distinct members, such that the order of selection does not matter (unlike permutations). For example, given three fruits, say an apple, an orange and a pear, there are three combinations of two that can be drawn from this set: an apple and a pear; an apple and an orange; or a pear and an orange. More formally, a ''k''-combination of a set ''S'' is a subset of ''k'' distinct elements of ''S''. So, two combinations are identical if and only if each combination has the same members. (The arrangement of the members in each set does not matter.) If the set has ''n'' elements, the number of ''k''-combinations, denoted by C(n,k) or C^n_k, is equal to the binomial coefficient \binom nk = \frac, which can be written using factorials as \textstyle\frac whenever k\leq n, and which is zero when k>n. This formula can be derived from the fact that each ''k''-combination of a set ''S'' of ''n'' members has k! permutat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JPEG XL
The JPEG XL Image Coding System is a royalty-free open standard for a image compression, compressed Raster graphics, raster image format. It defines a graphics file format and the abstract device for coding JPEG XL bitstreams. It is developed by the Joint Photographic Experts Group (JPEG) and standardized by the International Electrotechnical Commission (IEC) and the International Organization for Standardization (ISO) as the international standard ISO/IEC 18181. As a superset of JPEG/JFIF encoding, it features a compression mode built on a traditional block-based transform coding core. Additionally, there is a "modular mode" for synthetic image content and lossless compression. Optional lossy quantization (image processing), quantization enables both lossless and lossy compression. The name refers to the design committee (Joint Photographic Experts Group, JPEG), the ''X'' designates the series of its image coding standards published since 2000 (JPEG XT/JPEG XR, XR/JPEG XS, XS), an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DirectStorage
The Xbox Series X and Xbox Series S are the fourth generation of consoles in the Xbox series, succeeding the previous generation's Xbox One. Released on November 10, 2020, the higher-end Xbox Series X and lower-end Xbox Series S are part of the ninth generation of video game consoles, which also includes Sony's PlayStation 5, released the same month. Like the Xbox One, the consoles use an AMD 64-bit x86-64 CPU and GPU. Both models have solid-state drives to reduce loading times, support for hardware-accelerated ray-tracing and spatial audio, the ability to convert games to high-dynamic-range rendering using machine learning (Auto HDR), support for HDMI 2.1 variable refresh rate and low-latency modes, and updated controllers. Xbox Series X was designed to nominally render games in 2160p (4K resolution) at 60 frames per second (FPS). The lower-end, digital-only Xbox Series S, which has reduced specifications and does not include an optical drive, was designed to nominally re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsoft
Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The early 1980s and home computers, rise of personal computers through software like Windows, and the company has since expanded to Internet services, cloud computing, video gaming and other fields. Microsoft is the List of the largest software companies, largest software maker, one of the Trillion-dollar company, most valuable public U.S. companies, and one of the List of most valuable brands, most valuable brands globally. Microsoft was founded by Bill Gates and Paul Allen to develop and sell BASIC interpreters for the Altair 8800. It rose to dominate the personal computer operating system market with MS-DOS in the mid-1980s, followed by Windows. During the 41 years from 1980 to 2021 Microsoft released 9 versions of MS-DOS with a median frequen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dropbox (service)
Dropbox is a file hosting service operated by the American company Dropbox, Inc., headquartered in San Francisco, California, that offers cloud storage, file synchronization, personal cloud, and client software. Dropbox was founded in 2007 by MIT students Drew Houston and Arash Ferdowsi as a startup company, with initial funding from seed accelerator Y Combinator. Dropbox has experienced criticism and generated controversy for issues including security breaches and privacy concerns. Concept Dropbox brings files together in one central place by creating a special folder on the user's computer. The contents of these folders are synchronized to Dropbox's servers and to other computers and devices where the user has installed Dropbox, keeping the same files up-to-date on all devices. Dropbox uses a freemium business model, where users are offered a free account with set storage size, with paid subscriptions available that offer more capacity and additional features. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NVIDIA
Nvidia Corporation ( ) is an American multinational corporation and technology company headquartered in Santa Clara, California, and incorporated in Delaware. Founded in 1993 by Jensen Huang (president and CEO), Chris Malachowsky, and Curtis Priem, it designs and supplies graphics processing units (GPUs), application programming interfaces (APIs) for data science and high-performance computing, and system on a chip units (SoCs) for mobile computing and the automotive market. Nvidia is also a leading supplier of artificial intelligence (AI) hardware and software. Nvidia outsources the manufacturing of the hardware it designs. Nvidia's professional line of GPUs are used for edge-to-cloud computing and in supercomputers and workstations for applications in fields such as architecture, engineering and construction, media and entertainment, automotive, scientific research, and manufacturing design. Its GeForce line of GPUs are aimed at the consumer market and are used in ap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SAMtools
SAMtools is a set of utilities for interacting with and post-processing short DNA sequence read alignments in the SAM (Sequence Alignment/Map), BAM (Binary Alignment/Map) and CRAM formats, written by Heng Li. These files are generated as output by short read aligners like BWA. Both simple and advanced tools are provided, supporting complex tasks like variant calling and alignment viewing as well as sorting, indexing, data extraction and format conversion. SAM files can be very large (tens of Gigabytes is common), so compression is used to save space. SAM files are human-readable text files, and BAM files are simply their binary equivalent, whilst CRAM files are a restructured column-oriented binary container format. BAM files are typically compressed and more efficient for software to work with than SAM. SAMtools makes it possible to work directly with a compressed BAM file, without having to uncompress the whole file. Additionally, since the format for a SAM/BAM file is somewha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CRAM (file Format)
Compressed Reference-oriented Alignment Map (CRAM) is a compressed columnar file format for storing biological sequences aligned to a reference sequence, initially devised by Markus Hsi-Yang Fritz ''et al''. CRAM was designed to be an efficient reference-based alternative to the Sequence Alignment Map (SAM) and Binary Alignment Map (BAM) file formats. It optionally uses a genomic reference to describe differences between the aligned sequence fragments and the reference sequence, reducing storage costs. Additionally each column in the SAM format is separated into its own blocks, improving compression ratio. CRAM files typically vary from 30 to 60% smaller than BAM, depending on the data held within them. Implementations of CRAM exist in htsjdk, , JBrowse, and Scramble. The file format specification is maintained by the Global Alliance for Genomics and Health (GA4GH) with the specification document available from the EBI cram toolkit page. File format The basic structu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universal Scene Description
Universal Scene Description (USD) is a framework for interchange of 3D computer graphics data. The framework focuses on collaboration, non-destructive editing, and enabling multiple views and opinions about graphics data. USD is used in many industries including visual effects, architecture, design, robotics, CAD, and rendering. History It is developed by Pixar and was first published as open source software in 2016, under a modified Apache license. Pixar, Adobe, Apple, Autodesk, and NVIDIA, together with the Joint Development Foundation (JDF) of the Linux Foundation, announced the Alliance for OpenUSD (AOUSD) on August 1, 2023 to "promote the standardization, development, evolution, and growth of Pixar's Universal Scene Description technology." File formats File formats used by the specification include: * , which can be either ASCII or binary-encoded * , ASCII encoded * , binary encoded * , a package file which is a zero-compression, unencrypted zip archive, which m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
