view release on metacpan or  search on metacpan

gfl-image.html  view on Meta::CPAN

<P>
<H2><A NAME="gfl::image>enablelzw">GFL::Image-&gt;enableLZW</A></H2>
<P>If you've got a patent from UNISIS, you may enable LZW compression (this is class wide).
This compression algorithm is used by GIF &amp; TIFF formats.</P>
<P>Always the same sad story...</P>
<P>
<H2><A NAME="gfl::image>dumpallformats or dumpallformats()">GFL::Image-&gt;DumpAllFormats or <CODE>dumpallformats()</CODE></A></H2>
<P>Issue the complete list of supported formats with description and Read/Write flag.</P>
<P>
<HR>
<H1><A NAME="error handling">ERROR HANDLING</A></H1>
<P>Well, TIMTOWTDI...</P>
<P>To begin with, all methods except <STRONG>get()</STRONG> bring back a status report which is different
in LIST and SCALAR context.</P>
<UL>
<LI>
Error reporting in LIST context
<P>Here, you are testing for <EM>error</EM>. You get a list with two values :</P>
<P>- first value is <STRONG>true</STRONG> if the function <STRONG>failed</STRONG>, false otherwise.</P>
<P>- second value is either an error string or the string <CODE>'OK'</CODE></P>
<P>e.g:</P>
<PRE>
        @error = $a -&gt; rotate(100);
        if ($error[0])
        {
                print STDERR $error[1];
        }</PRE>
<P></P>
<LI>
Error reporting in SCALAR context
<P>Here, you are testing for <EM>Success</EM>.
You get <STRONG>true</STRONG> if the method <STRONG>succeeded</STRONG>, false otherwise.</P>
<P>e.g:</P>
<PRE>
        $a-&gt; rotate(100) &amp;&amp; $success++;</PRE>
<P></P>
<LI>
error reporting via <STRONG>LastError</STRONG> attribute
<P>In either SCALAR or LIST context, the <STRONG>LastError</STRONG> attribute is always updated with
false or an error message after a method call.</P>
<P>As using <CODE>get()</CODE> would also affect <CODE>lasterror</CODE>, you must retrieve it via the special accessor <CODE>-&gt;lasterror</CODE>.</P>
<P>Thus, you can say:</P>
<PRE>
        $b = $a -&gt; get('dither');
        $errormsg = $a -&gt;lasterror and print &quot;couldn't get dither value : $errormsg\n&quot;;</PRE>
<P></P>
<LI>
error reporting on STDERR
<P>See the <A HREF="#item_Verbose">Verbose</A> attribute if you want reports on STDERR.</P>
<P></P></UL>
<P>
<HR>
<H1><A NAME="copyright">COPYRIGHT</A></H1>
<P>copyright 2001
Germain Garand (<A HREF="mailto:germain@ebooksfrance.com">germain@ebooksfrance.com</A>)</P>
<P>This wrapper is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.</P>
<P>
<HR>
<H1><A NAME="see also">SEE ALSO</A></H1>
<P>GD(3), Image::Magick(3)</P>

</BODY>

</HTML>