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<h1 class="headline">Template::Plugin::Image</h1>
<h2 class="subhead">Plugin access to image sizes</h1>
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<h1 id="contents" onclick="switch_section(this)" title="Click title to show/hide section content.">Contents</h1>
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<ul class="toc">
<li class=""><a href="#SYNOPSIS">SYNOPSIS</a></li>
<li class=""><a href="#DESCRIPTION">DESCRIPTION</a></li>
<li class=""><a href="#CATCHING_ERRORS">CATCHING ERRORS</a></li>
<li class=""><a href="#USING_Image_Info">USING Image::Info</a></li>
<li class="sub"><a href="#section_file_media_type">file_media_type</a></li>
<li class="sub"><a href="#section_file_ext">file_ext</a></li>
<li class="sub"><a href="#section_color_type">color_type</a></li>
<li class="sub"><a href="#section_resolution">resolution</a></li>
<li class="sub"><a href="#section_SamplesPerPixel">SamplesPerPixel</a></li>
<li class="sub"><a href="#section_BitsPerSample">BitsPerSample</a></li>
<li class="sub"><a href="#section_Comment">Comment</a></li>
<li class="sub"><a href="#section_Interlace">Interlace</a></li>
<li class="sub"><a href="#section_Compression">Compression</a></li>
<li class="sub"><a href="#section_Gamma">Gamma</a></li>
<li class=""><a href="#AUTHOR">AUTHOR</a></li>
<li class=""><a href="#COPYRIGHT">COPYRIGHT</a></li>
<li class=""><a href="#SEE_ALSO">SEE ALSO</a></li>
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<div class="section">
<div class="head">
<h1 id="SYNOPSIS" onclick="switch_section(this)" title="Click title to show/hide section content.">SYNOPSIS</h1>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
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<div class="body">
<pre><span class="tt">[% USE Image(filename) %]</span>
<span class="tt">[% Image.width %]</span>
<span class="tt">[% Image.height %]</span>
<span class="tt">[% Image.size.join(', ') %]</span>
<span class="tt">[% Image.attr %]</span>
<span class="tt">[% Image.tag %]</span></pre>
</div>
</div>
<div class="section">
<div class="head">
<h1 id="DESCRIPTION" onclick="switch_section(this)" title="Click title to show/hide section content.">DESCRIPTION</h1>
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<div class="body">
<p>
This plugin provides an interface to the <a href="http://search.cpan.org/search?query=Image::Info&mode=all">Image::Info</a> or <a href="http://search.cpan.org/search?query=Image::Size&mode=all">Image::Size</a> modules for determining the
size of image files.
</p>
<p>
You can specify the plugin name as either '<code>Image</code>' or
'<code>image</code>'. The plugin object created will then have the same
name. The file name of the image should be specified as a positional or
named argument.
</p>
<pre><span class="tt">[% # all these are valid, take your pick %]</span>
<span class="tt">[% USE Image('foo.gif') %]</span>
<span class="tt">[% USE image('bar.gif') %]</span>
<span class="tt">[% USE Image 'ping.gif' %]</span>
<span class="tt">[% USE image(name='baz.gif') %]</span>
<span class="tt">[% USE Image name='pong.gif' %]</span></pre>
<p>
A <code>root</code> parameter can be used to specify the location of the
image file:
</p>
<pre><span class="tt">[% USE Image(root='/path/to/root', name='images/home.png') %]</span>
# image path: /path/to/root/images/home.png
# img src: images/home.png</pre>
<p>
In cases where the image path and image url do not match up, specify the
file name directly:
</p>
<pre><span class="tt">[% USE Image(file='/path/to/home.png', name='/images/home.png') %]</span></pre>
<p>
The <code>alt</code> parameter can be used to specify an alternate name
for the image, for use in constructing an XHTML element (see the
<code>tag()</code> method below).
</p>
<pre><span class="tt">[% USE Image('home.png', alt="Home") %]</span></pre>
<p>
You can also provide an alternate name for an <code>Image</code> plugin
object.
</p>
<pre><span class="tt">[% USE img1 = image 'foo.gif' %]</span>
<span class="tt">[% USE img2 = image 'bar.gif' %]</span></pre>
<p>
The <code>name</code> method returns the image file name.
</p>
<pre><span class="tt">[% img1.name %]</span> # foo.gif</pre>
<p>
The <code>width</code> and <code>height</code> methods return the width
and height of the image, respectively. The <code>size</code> method
returns a reference to a 2 element list containing the width and height.
</p>
<pre><span class="tt">[% USE image 'foo.gif' %]</span>
width: <span class="tt">[% image.width %]</span>
height: <span class="tt">[% image.height %]</span>
size: <span class="tt">[% image.size.join(', ') %]</span></pre>
<p>
The <code>modtime</code> method returns the modification time of the file
in question, suitable for use with the <a href="../../../modules/Template/Plugin/Date.html">Date</a> plugin, for example:
</p>
<pre><span class="tt">[% USE image 'foo.gif' %]</span>
<span class="tt">[% USE date %]</span>
<span class="tt">[% date.format(image.modtime, "%B, %e %Y") %]</span></pre>
<p>
The <code>attr</code> method returns the height and width as HTML/XML
attributes.
</p>
<pre><span class="tt">[% USE image 'foo.gif' %]</span>
<span class="tt">[% image.attr %]</span></pre>
<p>
Typical output:
</p>
<pre>width="60" height="20"</pre>
<p>
The <code>tag</code> method returns a complete XHTML tag referencing the
image.
</p>
<pre><span class="tt">[% USE image 'foo.gif' %]</span>
<span class="tt">[% image.tag %]</span></pre>
<p>
Typical output:
</p>
<pre><img src="foo.gif" width="60" height="20" alt="" /></pre>
<p>
You can provide any additional attributes that should be added to the
XHTML tag.
</p>
<pre><span class="tt">[% USE image 'foo.gif' %]</span>
<span class="tt">[% image.tag(class="logo" alt="Logo") %]</span></pre>
<p>
Typical output:
</p>
<pre><img src="foo.gif" width="60" height="20" alt="Logo" class="logo" /></pre>
<p>
Note that the <code>alt</code> attribute is mandatory in a strict XHTML
<code>img</code> element (even if it's empty) so it is always added even
if you don't explicitly provide a value for it. You can do so as an
argument to the <code>tag</code> method, as shown in the previous
example, or as an argument
</p>
<pre><span class="tt">[% USE image('foo.gif', alt='Logo') %]</span></pre>
</div>
</div>
<div class="section">
<div class="head">
<h1 id="CATCHING_ERRORS" onclick="switch_section(this)" title="Click title to show/hide section content.">CATCHING ERRORS</h1>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
If the image file cannot be found then the above methods will throw an
<code>Image</code> error. You can enclose calls to these methods in a
<code>TRY...CATCH</code> block to catch any potential errors.
</p>
<pre><span class="tt">[% TRY;
image.width;
CATCH;
error; # print error
END
%]</span></pre>
</div>
</div>
<div class="section">
<div class="head">
<h1 id="USING_Image_Info" onclick="switch_section(this)" title="Click title to show/hide section content.">USING Image::Info</h1>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
At run time, the plugin tries to load <a href="http://search.cpan.org/search?query=Image::Info&mode=all">Image::Info</a> in preference to <a href="http://search.cpan.org/search?query=Image::Size&mode=all">Image::Size</a>. If <a href="http://search.cpan.org/search?query=Image::Info&mode=all">Image::Info</a> is found, then some additional methods are
available, in addition to <code>size</code>, <code>width</code>,
<code>height</code>, <code>attr</code>, and <code>tag</code>. These
additional methods are named after the elements that <a href="http://search.cpan.org/search?query=Image::Info&mode=all">Image::Info</a> retrieves from the image
itself. The types of methods available depend on the type of image (see
<a href="http://search.cpan.org/search?query=Image::Info&mode=all">Image::Info</a> for more
details). These additional methods will always include the following:
</p>
<div class="subsection">
<div class="head">
<h2 id="section_file_media_type" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">file_media_type</h2>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
This is the MIME type that is appropriate for the given file format. The
corresponding value is a string like: "<code>image/png</code>" or
"<code>image/jpeg</code>".
</p>
</div>
</div> <div class="subsection">
<div class="head">
<h2 id="section_file_ext" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">file_ext</h2>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
The is the suggested file name extention for a file of the given file
format. The value is a 3 letter, lowercase string like
"<code>png</code>", "<code>jpg</code>".
</p>
</div>
</div> <div class="subsection">
<div class="head">
<h2 id="section_color_type" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">color_type</h2>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
The value is a short string describing what kind of values the pixels
encode. The value can be one of the following:
</p>
<pre>Gray
GrayA
RGB
RGBA
CMYK
YCbCr
CIELab</pre>
<p>
These names can also be prefixed by "<code>Indexed-</code>" if the image
is composed of indexes into a palette. Of these, only
"<code>Indexed-RGB</code>" is likely to occur.
</p>
<p>
(It is similar to the TIFF field PhotometricInterpretation, but this name
was found to be too long, so we used the PNG inpired term instead.)
</p>
</div>
</div> <div class="subsection">
<div class="head">
<h2 id="section_resolution" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">resolution</h2>
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</div>
<div class="body">
<p>
The value of this field normally gives the physical size of the image on
screen or paper. When the unit specifier is missing then this field
denotes the squareness of pixels in the image.
</p>
<p>
The syntax of this field is:
</p>
<pre><res> <unit>
<xres> "/" <yres> <unit>
<xres> "/" <yres></pre>
<p>
The <code><res></code>, <code><xres></code> and
<code><yres></code> fields are numbers. The
<code><unit></code> is a string like <code>dpi</code>,
<code>dpm</code> or <code>dpcm</code> (denoting "dots per inch/cm/meter).
</p>
</div>
</div> <div class="subsection">
<div class="head">
<h2 id="section_SamplesPerPixel" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">SamplesPerPixel</h2>
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</div>
<div class="body">
<p>
This says how many channels there are in the image. For some image
formats this number might be higher than the number implied from the
<code>color_type</code>.
</p>
</div>
</div> <div class="subsection">
<div class="head">
<h2 id="section_BitsPerSample" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">BitsPerSample</h2>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
This says how many bits are used to encode each of samples. The value is
a reference to an array containing numbers. The number of elements in the
array should be the same as <code>SamplesPerPixel</code>.
</p>
</div>
</div> <div class="subsection">
<div class="head">
<h2 id="section_Comment" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">Comment</h2>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
Textual comments found in the file. The value is a reference to an array
if there are multiple comments found.
</p>
</div>
</div> <div class="subsection">
<div class="head">
<h2 id="section_Interlace" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">Interlace</h2>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
If the image is interlaced, then this returns the interlace type.
</p>
</div>
</div> <div class="subsection">
<div class="head">
<h2 id="section_Compression" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">Compression</h2>
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</div>
<div class="body">
<p>
This returns the name of the compression algorithm is used.
</p>
</div>
</div> <div class="subsection">
<div class="head">
<h2 id="section_Gamma" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">Gamma</h2>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
A number indicating the gamma curve of the image (e.g. 2.2)
</p>
</div>
</div>
</div>
</div>
<div class="section">
<div class="head">
<h1 id="AUTHOR" onclick="switch_section(this)" title="Click title to show/hide section content.">AUTHOR</h1>
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</div>
<div class="body">
<p>
Andy Wardley <abw@wardley.org> <a
href="http://wardley.org/">http://wardley.org/</a>
</p>
</div>
</div>
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<h1 id="COPYRIGHT" onclick="switch_section(this)" title="Click title to show/hide section content.">COPYRIGHT</h1>
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<div class="body">
<p>
Copyright (C) 1996-2007 Andy Wardley. All Rights Reserved.
</p>
<p>
This module is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
</p>
</div>
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<h1 id="SEE_ALSO" onclick="switch_section(this)" title="Click title to show/hide section content.">SEE ALSO</h1>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
<a href="../../../modules/Template/Plugin.html">Template::Plugin</a>, <a
href="http://search.cpan.org/search?query=Image::Info&mode=all">Image::Info</a>
</p>
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<div class="licence">
The <a href="http://template-toolkit.org/">Template Toolkit</a> is <a href="http://opensource.org/">Open Source</a> software.
You can redistribute and/or modify it under the terms of the <a href="http://www.opensource.org/licenses/gpl-license.php">GNU Public Licence</a>
or the <a href="http://www.opensource.org/licenses/artistic-license.php">Perl Artistic Licence</a>.
</div>
</div>
<div id="palette">
<ul>
<li class="first"><a href="#" class="blue" onclick="set_style('Clear Blue')"></a></li>
<li><a href="#" class="orange" onclick="set_style('Clear Orange')"></a></li>
<li><a href="#" class="green" onclick="set_style('Clear Green')"></a></li>
<li><a href="#" class="purple" onclick="set_style('Clear Purple')"></a></li>
<li><a href="#" class="grey" onclick="set_style('Clear Grey')"></a></li>
</ul>
</div>
</div> </body>
</html>