The first char is emitted as simply that, an 8 bit value. Following that point all codes are emitted in longer than 8 bit form (starting with 9 bits until the table grows to have 512 values, then to 10 bits etc.).
A historical side-note: Years back I was doing some patent analysis, and read the Unisys LZW patent carefully several times.
Expanding the table to increasing the output byte width is Welch's improvement to the Lempel-Ziv compression algorithm, and this is what Unisys obtained a patent on. If you crippled your compression such that the table never grew past 256 values, you weren't infringing (in my "Not A Lawyer" opinion). Unisys allowed some FUD to surround this issue, not correcting the impression that it was GIF they held a patent on. Not so.
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.
|
