Data compression

thumbtime=1|thumb|upright=1.5|A one-minute animated video showing an example of a media production process|alt=Scenes in order: initial meeting, brainstorming, concept design, scripting, storyboards, shooting, initial editing, adding graphics, revising, add audio, final grading, delivery

MP3 (formally MPEG-1 Audio Layer III or MPEG-2 Audio Layer III) is an audio coding format developed largely by the Fraunhofer Society in Germany under the lead of Karlheinz Brandenburg. It was designed to greatly reduce the amount of data required to represent audio, yet still sound like a faithful reproduction of the original uncompressed audio to most listeners; for example, compared to CD-quality digital audio, MP3 compression can commonly achieve a 75–95% reduction in size, depending on the bit rate. In popular usage, MP3 often refers to files of sound or music recordings stored in the MP3

mathematical theory from the field of probability theory and statistics

process of encoding information using fewer bits than the original representation

number of distinct pixels in each dimension that can be displayed

A codec is a computer hardware or software component that encodes or decodes a data stream or signal. Codec is a portmanteau of coder/decoder.

expected value of the amount of information delivered by a message

random signal having equal intensity at different frequencies, giving it a constant power spectral density

information transmission rate expressed in bits per second

measure of frequency of image frames in video

entropy encoding algorithm used for lossless data compression

theorem in signal processing describing discrete samples of a continuous signal

process of mapping a continuous set to a countable set

data compression approach allowing perfect reconstruction of the original data

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.

data compression approach that results in loss or change of some data

standard that defines a specific range of colors

technique representing data as sums of cosine functions

video displaying technique

reduction of image size to save storage and transmission costs

in information theory, extra bits transmitted without adding information

notation for expressing geographic annotation and visualization within Internet-based maps

measure of algorithmic complexity

simple form of data compression in which runs of data (sequences in which the same data value occurs in many consecutive data elements) are stored as a single data value and count

Lempel–Ziv–Welch (LZW) is a universal lossless compression algorithm created by Abraham Lempel, Jacob Ziv, and Terry Welch. It was published by Welch in 1984 as an improvement to the LZ78 algorithm published by Lempel and Ziv in 1978. Claimed advantages include: simple to implement and the potential for high throughput in a hardware implementation.

ARJ (Archived by Robert Jung) is a software tool designed in 1991 by Robert K. Jung for creating high-efficiency compressed file archives. ARJ is currently on version 2.86 for MS-DOS and 3.31 for Microsoft Windows and supports 16-bit, 32-bit and 64-bit Intel architectures.

apparatus or software that can transform video data into a coded format with different characteristics and/or back

In computing, Deflate (stylized as DEFLATE, and also called Flate) is a lossless data compression algorithm that uses a combination of LZ77 and Huffman coding. It was designed by Phil Katz, for version 2 of his PKZIP archiving tool. Deflate was later specified in Request for Comments (RFC) 1951 (1996).

algorithm used in data compression techniques

LZMA (Lempel–Ziv–Markov chain algorithm) is a lossless data compression algorithm developed since 1998 by Igor Pavlov, the developer of 7-Zip. It has been used in the 7z format of the 7-Zip archiver since 2001. This algorithm uses a dictionary compression scheme somewhat similar to the LZ77 algorithm published by Abraham Lempel and Jacob Ziv in 1977 and features a high compression ratio (generally higher than bzip2) and a variable compression-dictionary size (up to 4 GB), while still maintaining decompression speed similar to other commonly used compression algorithms.

technique for constructing a prefix code

data processing technique to eliminate duplicate copies of repeating data

form of entropy encoding used in lossless data compression

method of digital image compression using fractals

noticeable distortion of media caused by the application of lossy data compression

technique used to encode voices in telephony

encoding images using a lower resolution for chroma channels

mathematical technique used in data compression and analysis

rate control method that allows the bit rate of a multimedia file to vary over time

lossless data compression method

speech analysis and encoding technique

Data compression theory

audio companding algorithm

Zstandard is a lossless data compression algorithm developed by Yann Collet at Facebook. Zstd is the corresponding reference implementation in C, released as open-source software on 31 August 2016.

signal encoder

lossless data compression scheme that is independent of the specific characteristics of the medium

error in the perception or representation of any visual or aural information

signal conversion technique

uniquely decodable code where, given a complete and accurate sequence, a receiver can identify each word without requiring a special marker between words

thumb|upright=1.5|A signal before (top) and after μ-law algorithm|μ-law compression (bottom)

device or program that encodes/decodes audio data in some bitstream format

abbreviations used by ancient and medieval scribes writing in Latin, and later in Greek, Old Norse and other European languages

algorithm

Compression algorithm

measurement of the power of a data compression algorithm

lossy audio compression applied to human speech

Entropy encoding

Brotli is a lossless data compression algorithm developed by Jyrki Alakuijala and Zoltán Szabadka. It uses a combination of the general-purpose LZ77 lossless compression algorithm, Huffman coding and 2nd-order context modelling. Brotli is primarily used by web servers and content delivery networks to compress HTTP content, making internet websites load faster. As successor to gzip, it is supported by all major web browsers and has become increasingly popular, as it provides better compression than gzip.

storing or transmitting data in the form of differences (deltas) between sequential data, as opposed to complete files