Data Compression


Criteria

Survey Formats

Basics

Compression Methods

Shannon-Fano

Huffman

Lempel-Ziv (LZ)

Arithmetic Coding

Run Length Encoding

Burrows-Wheeler (BWT)

Implementations

Deflate

Basic Algorithm

Data Structure

Huffman Code Trees

Data and Lengths

Distance

Static and Dynamic

Deflate64™

Data Formats


Glossary

Index


Download


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Deflate: Distance Tree


The Huffman tree addressing previously used sequences provides a similar structure like the one for length codes. Beside the basic codes (0 - 29) between 0 and 13 extra bits are specified.


In this manner the range of values for the distances is 1 to 32,768. The latter is the maximum limit for the sliding window used as dictionary. Any sequence outside this window is not addressable.


Although the data are structured into blocks, a sequences may be addressed from any preceding block. The limit of 32,768 byte (32 kbyte) is independent from the particular block sizes.


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Deflate Deflate: Code Tree for Original Data and Sequence Lengths Deflate: Static and Dynamic Code Trees