A Java library for binary coding
The coding library builds on the bits library, to provide a range entropy codings, both universal and non. Full javadocs are available.
The library currently supports the following universal codings.
- Elias Delta
- Elias Omega
- Fibonacci
- Golomb / Rice
- Unary
All universal codings support arbitrarily large numbers via BigInteger.
In addition to universal codings, the following non-universal codings are supported.
- Huffman
- Truncated Binary
The Huffman implementation in particular has seen lots of work: it accelerates encoding through canonicalization and block reads bits for faster decoding (without a some degree of read-ahead, I’m not sure there’s a faster approach). It can also return a dictionary which contains the minimal state needed to reconstruct the encoding. This can be efficiently transmitted ahead of a compressed message.
A number of helpful classes are provided in addition to the core coding implementations.
ExtendedCodingwraps a coding to provide canonical encoding of numerical valuesCodedReader/CodedWriterconveniently pairs an ExtendedCoding with a BitReader/BitWriterCodedStreamsprovides static utility methods for common encoding and decoding tasks.CharFrequencyRecorderaccumulates character frequencies from Strings and other sources of character data; useful for Huffman coding.CodingFrequenciescalculates ‘zero-order’ information entropy from data arrays.
The coding library is available from the Maven central repository:
Group ID:
com.tomgibara.codingArtifact ID:codingVersion:1.0.1
The Maven dependency being:
<dependency>
<groupId>com.tomgibara.coding</groupId>
<artifactId>coding</artifactId>
<version>1.0.1</version>
</dependency>
2016.11.19 Version 1.0.1
- Built against newest dependency versions.
- Java dependency promoted to Java 1.8
2015.05.26 Version 1.0.0-j6
Java 6 compatible release
2015.05.25 Version 1.0.0
Initial release