Glossary of Compression Words
- A file archiver with a high compression ratio.
- Alpha blending
The process of combining an image with a background to create the appearance of partial or full transparency.
- Alpha channel
An additional channel (in addition to RGB) that contains a value between 0 and 1 that designates the transparency for each pixel.
- Alpha transparency
The transparency value for a pixel as transmitted in the Alpha channel.
- Arithmetic coding
An algorithm for encoding data, wherein frequently used characters are stored with fewer bits and not-so-frequently occurring characters are stored with more bits, resulting in fewer bits used in total. Rather than assigning codewords to symbols in a 1:1 fashion, this algorithm transforms the entire input stream from a set of symbols to one (excessively long) numeric value, whose LOG2 representation is closer to the true value of entropy for the stream.
See Chapter 5.
- Asymmetric numeral systems (ANS)
A modern variant of statistical compression, which has shown early promise in achieving close to entropy compression with performance comparable to Huffman coding.
See Chapter 5.
- Binary or base 2 number system
A way of representing numbers using only the digits 0 and 1, and each shift in position is by a power of 2. For example, the decimal number 5 would be 101 or 20 + 22.
See Chapter 2.
- Binary erasure channel
A communications channel model used for analysis in information theory. The idea is that ...