http://fileformats.archiveteam.org/index.php?action=history&feed=atom&title=Huffman_coding 2026-04-07T04:52:26Z Revision history for this page on the wiki MediaWiki 1.19.2 http://fileformats.archiveteam.org/index.php?title=Huffman_coding&diff=39193&oldid=prev 2021-01-20T14:36:53Z

<p></p> <table class='diff diff-contentalign-left'> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">← Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 14:36, 20 January 2021</td> </tr><tr><td colspan="2" class="diff-lineno">Line 3:</td> <td colspan="2" class="diff-lineno">Line 3:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>|subcat=Compression</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>|subcat=Compression</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>|pronom={{PRONOM|x-cmp/19}}</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>|pronom={{PRONOM|x-cmp/19}}</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">|wikidata={{wikidata|Q2647}}</ins></div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>}}</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>}}</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>'''Huffman coding''' is a kind of lossless data compression.</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>'''Huffman coding''' is a kind of lossless data compression.</div></td></tr> <tr><td colspan="2" class="diff-lineno">Line 15:</td> <td colspan="2" class="diff-lineno">Line 16:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>Unfortunately, the widely-used terms &quot;static Huffman&quot; and &quot;dynamic Huffman&quot; are at least somewhat ambiguous. They don't have the same meanings to all authors.</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>Unfortunately, the widely-used terms &quot;static Huffman&quot; and &quot;dynamic Huffman&quot; are at least somewhat ambiguous. They don't have the same meanings to all authors.</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">=== Terminology ===</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">Technically, ''Huffman coding'' is a specific algorithm that finds a bit-oriented ''prefix code''. The code it finds would then be called a '''Huffman code'''.</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">For formats that use [[adaptive Huffman coding]], the decompressor must use the same algorithm as the compressor.</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">But in most other cases, the algorithm used by the compressor is irrelevant to the decompressor. So the compressor does not have to use the Huffman coding algorithm at all, even if the format specification calls for it. It could use something similar like [[Shannon–Fano coding]], or something completely different. Everything will still work. Much format documentation, including this wiki, still uses the term ''Huffman coding'' in such cases, though it's a slight abuse of terminology.</ins></div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>== See also ==</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>== See also ==</div></td></tr> <tr><td colspan="2" class="diff-lineno">Line 21:</td> <td colspan="2" class="diff-lineno">Line 29:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[LZ77 with Huffman coding]]</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[LZ77 with Huffman coding]]</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[Modified Huffman]]</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[Modified Huffman]]</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">* [[Shannon–Fano coding]]</ins></div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>== External links ==</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>== External links ==</div></td></tr> <tr><td class='diff-marker'>−</td><td style="background: #ffa; color:black; font-size: smaller;"><div>* [[Wikipedia:Huffman coding<del class="diffchange diffchange-inline">|</del>Wikipedia <del class="diffchange diffchange-inline">article</del>]]</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>* [[Wikipedia: Huffman coding<ins class="diffchange diffchange-inline">]]</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins class="diffchange diffchange-inline">* [[</ins>Wikipedia<ins class="diffchange diffchange-inline">: Prefix code</ins>]]</div></td></tr> </table>

Jsummers http://fileformats.archiveteam.org/index.php?title=Huffman_coding&diff=37951&oldid=prev 2020-09-12T11:42:37Z

<p>‎<span dir="auto"><span class="autocomment">See also</span></span></p> <table class='diff diff-contentalign-left'> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">← Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 11:42, 12 September 2020</td> </tr><tr><td colspan="2" class="diff-lineno">Line 19:</td> <td colspan="2" class="diff-lineno">Line 19:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[Adaptive Huffman coding]]</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[Adaptive Huffman coding]]</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[Canonical Huffman code]]</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[Canonical Huffman code]]</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">* [[LZ77 with Huffman coding]]</ins></div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[Modified Huffman]]</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[Modified Huffman]]</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>== External links ==</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>== External links ==</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[Wikipedia:Huffman coding|Wikipedia article]]</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[Wikipedia:Huffman coding|Wikipedia article]]</div></td></tr> </table>

Jsummers http://fileformats.archiveteam.org/index.php?title=Huffman_coding&diff=37793&oldid=prev 2020-08-27T19:42:18Z

<p></p> <table class='diff diff-contentalign-left'> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">← Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 19:42, 27 August 2020</td> </tr><tr><td colspan="2" class="diff-lineno">Line 8:</td> <td colspan="2" class="diff-lineno">Line 8:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>Symbols (such as bytes) are encoded as variable-length bit strings, optimized such that the more common symbols use shorter bit strings. No bit string is allowed to be a prefix of another bit string, which makes it possible for the decoder to deduce when a string has ended.</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>Symbols (such as bytes) are encoded as variable-length bit strings, optimized such that the more common symbols use shorter bit strings. No bit string is allowed to be a prefix of another bit string, which makes it possible for the decoder to deduce when a string has ended.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>−</td><td style="background: #ffa; color:black; font-size: smaller;"><div><del class="diffchange diffchange-inline">The code table used </del>may <del class="diffchange diffchange-inline">be </del>stored in the <del class="diffchange diffchange-inline">compressed </del>file, <del class="diffchange diffchange-inline">or it may </del>be a predefined <del class="diffchange diffchange-inline">table </del>known to both the encoder and decoder.</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins class="diffchange diffchange-inline">== Discussion ==</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins class="diffchange diffchange-inline">A format </ins>may <ins class="diffchange diffchange-inline">use Huffman coding in a number of different ways, including:</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins class="diffchange diffchange-inline">* The codebook is created automatically as the data is processed ([[Adaptive Huffman coding]]).</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins class="diffchange diffchange-inline">* The codebook is </ins>stored in the file, <ins class="diffchange diffchange-inline">to </ins>be <ins class="diffchange diffchange-inline">read before the encoded data. Sometimes the compressed data is split into segments, which each segment having </ins>a <ins class="diffchange diffchange-inline">different codebook.</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins class="diffchange diffchange-inline">* The codebook is </ins>predefined<ins class="diffchange diffchange-inline">, and </ins>known to both the encoder and decoder<ins class="diffchange diffchange-inline">. Note that there is no fundamental distinction between a predefined Huffman code, and a variable-length integer code that wouldn't necessarily be called &quot;Huffman&quot;.</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>&#160;</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins class="diffchange diffchange-inline">Unfortunately, the widely-used terms &quot;static Huffman&quot; and &quot;dynamic Huffman&quot; are at least somewhat ambiguous. They don't have the same meanings to all authors</ins>.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>== See also ==</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>== See also ==</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">* [[Adaptive Huffman coding]]</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">* [[Canonical Huffman code]]</ins></div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[Modified Huffman]]</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[Modified Huffman]]</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>== External links ==</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>== External links ==</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[Wikipedia:Huffman coding|Wikipedia article]]</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[Wikipedia:Huffman coding|Wikipedia article]]</div></td></tr> </table>

Jsummers http://fileformats.archiveteam.org/index.php?title=Huffman_coding&diff=10294&oldid=prev 2013-03-07T06:30:59Z

<p>PRONOM ID</p> <table class='diff diff-contentalign-left'> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">← Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 06:30, 7 March 2013</td> </tr><tr><td colspan="2" class="diff-lineno">Line 2:</td> <td colspan="2" class="diff-lineno">Line 2:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>|formattype=electronic</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>|formattype=electronic</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>|subcat=Compression</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>|subcat=Compression</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">|pronom={{PRONOM|x-cmp/19}}</ins></div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>}}</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>}}</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>'''Huffman coding''' is a kind of lossless data compression.</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>'''Huffman coding''' is a kind of lossless data compression.</div></td></tr> </table>

Jsummers http://fileformats.archiveteam.org/index.php?title=Huffman_coding&diff=10087&oldid=prev 2013-02-26T17:35:09Z

<p></p> <table class='diff diff-contentalign-left'> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">← Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 17:35, 26 February 2013</td> </tr><tr><td colspan="2" class="diff-lineno">Line 8:</td> <td colspan="2" class="diff-lineno">Line 8:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>The code table used may be stored in the compressed file, or it may be a predefined table known to both the encoder and decoder.</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>The code table used may be stored in the compressed file, or it may be a predefined table known to both the encoder and decoder.</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">== See also ==</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">* [[Modified Huffman]]</ins></div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>== External links ==</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>== External links ==</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[Wikipedia:Huffman coding|Wikipedia article]]</div></td><td class='diff-marker'>&#160;</td><td style="background: #eee; color:black; font-size: smaller;"><div>* [[Wikipedia:Huffman coding|Wikipedia article]]</div></td></tr> </table>

Jsummers http://fileformats.archiveteam.org/index.php?title=Huffman_coding&diff=9945&oldid=prev 2013-02-23T13:48:29Z

<p>Created page with &quot;{{FormatInfo |formattype=electronic |subcat=Compression }} &#039;&#039;&#039;Huffman coding&#039;&#039;&#039; is a kind of lossless data compression. Symbols (such as bytes) are encoded as variable-length...&quot;</p> <p><b>New page</b></p><div>{{FormatInfo<br /> |formattype=electronic<br /> |subcat=Compression<br /> }}<br /> '''Huffman coding''' is a kind of lossless data compression.<br /> <br /> Symbols (such as bytes) are encoded as variable-length bit strings, optimized such that the more common symbols use shorter bit strings. No bit string is allowed to be a prefix of another bit string, which makes it possible for the decoder to deduce when a string has ended.<br /> <br /> The code table used may be stored in the compressed file, or it may be a predefined table known to both the encoder and decoder.<br /> <br /> == External links ==<br /> * [[Wikipedia:Huffman coding|Wikipedia article]]</div>

Jsummers