An audio compression technique where the sound is split into frequency bands and then parts of the signal which the ear cannot detect are removed, e.g. a quiet sound masked by a loud one. The remaining signal is encoded using variable bit-rates with more bits per sample being used in the mid frequency range. Subband encoding is used in MPEG-1. (1994-11-02)

In signal processing, sub-band coding (SBC) is any form of transform coding that breaks a signal into a number of different frequency bands, typically by using a fast Fourier transform, and encodes each one independently. This decomposition is often the first step in data compression for audio and video signals.

Memory has the ability to encode, store and recall information. Memories give an organism the capability to learn and adapt from previous experiences as well as build relationships.

character encoding

<character> The set of all characters onto which a {coded character set} maps integers (code positions). For example, consider these two simple coded character sets: Coded Character Set One: integer 0 -> the character "A" integer 1 -> the character "B" Coded Character Set Two: integer 0 -> the character "B" integer 1 -> the character "A" Both of these coded character sets map to the characters "A" and "B", so they have the same character repertoire. But since the mapping is different (and obviously incompatible), these are different coded character sets. (1998-12-17)

<character> (Or "character encoding scheme") A mapping of binary values to code positions and back; generally a 1:1 (bijective) mapping. In the case of ASCII, this is generally a f(x)=x mapping: code point 65 maps to the byte value 65, and vice versa. This is possible because ASCII uses only code positions representable as single bytes, i.e., values between 0 and 255, at most. (US-ASCII only uses values 0 to 127, in fact.) Unicode and many CJK coded character sets use many more than 255 positions, requiring more complex mappings: sometimes the characters are mapped onto pairs of bytes (see DBCS). In many cases, this breaks programs that assume a one-to-one mapping of bytes to characters, and so, for example, treat any occurrance of the byte value 13 as a carriage return. To avoid this problem, character encodings such as UTF-8 were devised. (1998-10-18)

<character> 1. A particular mapping between characters and byte strings, i.e. the combination of a particular character encoding (which maps between byte strings and integers) and a particular coded character set (which maps between integers and characters). For example: ASCII (the ASCII coded character set, encoded directly as single-byte values), or UTF-8 (the Unicode coded character set, encoded with an 8-bit transformation method). 2. Occasionally: a character repertoire; or a {coded character set}. (1998-12-17)

<character, standard> A mapping from a set of integers to a set of characters. This mapping is generally 1:1 (i.e., bijective), for example, the code position 65 in ASCII maps only to "A", and it's the only position that maps to "A". There are several standard coded character sets, the most widely used is ASCII, generally in its Latin-1 dialect, with Unicode becoming slowly more common; while EBCDIC and Baudot are extinct except in legacy systems. A coded character set may include letters, digits, punctuation, control codes, various mathematical and typographic symbols, and other characters. Each character in the set is represented by a unique character code (or "{code position}"). (1998-10-18)

Character Data Representation Architecture

Character encoding is the process of assigning numbers to graphical characters, especially the written characters of human language, allowing them to be stored, transmitted, and transformed using digital computers.Definition from The Tech Terms Dictionary The numerical values that make up a character encoding are known as "code points" and collectively comprise a "code space", a "code page", or a "character map".