<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en" dir="ltr">
<head>
<style type="text/css" media="screen,projection"><!--
@import url("../www/magick.css");
//--></style>
<meta name="verify-v1" content="g222frIIxcQTrvDR3NBRUSKP3AnMNoqxOkIniCEkV7U=" />
<link rel="meta" type="application/rdf+xml" title="ICI" href="http://imagemagick.org/ici.rdf" />
<title>ImageMagick: High Dynamic-Range Images</title>
<meta http-equiv="Content-Language" content="en-US"/>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<meta http-equiv="Reply-to" content="magick-users@imagemagick.org"/>
<meta name="Generator" content="PHP"/>
<meta name="Keywords" content="high, dynamic-range, images, ImageMagick, ImageMagic, MagickCore, MagickWand, PerlMagick, Magick++, RMagick, PythonMagick, JMagick, TclMagick, Image, Magick, Magic, Wand, ImageMagickObject"/>
<meta name="Description" content="ImageMagick® is a software suite to create, edit, and compose bitmap images. It can read, convert and write images in a variety of formats (about 100) including GIF, JPEG, JPEG-2000, PNG, PDF, PhotoCD, TIFF, and DPX. Use ImageMagick to translate, flip, mirror, rotate, scale, shear and transform images, adjust image colors, apply various special effects, or draw text, lines, polygons, ellipses and Bézier curves. ImageMagick is free software delivered as a ready-to-run binary distribution or as source code that you can freely use, copy, modify, and distribute. Its license is compatible with the GPL. It runs on all major operating systems. The functionality of ImageMagick is typically utilized from the command line or you can use the features from programs written in your favorite programming language. Choose from these interfaces: MagickCore (C), MagickWand (C), ChMagick (Ch), Magick++ (C++), JMagick (Java), L-Magick (Lisp), PascalMagick (Pascal), PerlMagick (Perl), MagickWand for PHP (PHP), PythonMagick (Python), RMagick (Ruby), or TclMagick (Tcl/TK). With a language interface, use ImageMagick to modify or create images automagically and dynamically."/>
<meta name="Rating" content="GENERAL"/>
<meta name="Robots" content="INDEX, FOLLOW"/>
<meta name="Generator" content="ImageMagick Studio LLC"/>
<meta name="Author" content="ImageMagick Studio LLC"/>
<meta name="Revisit-after" content="2 DAYS"/>
<meta name="Resource-type" content="document"/>
<meta name="Copyright" content="Copyright (c) 1999-2008 ImageMagick Studio LLC"/>
<meta name="Distribution" content="Global"/>
<link rel="shortcut icon" href="../images/wand.ico" type="images/vnd.microsoft.icon"/>
</head>
<body id="www-imagemagick-org">
<table id="titlebar" style="width: 100%;background-color: #f5f5f5" cellpadding="0" cellspacing="0" border="0" summary="ImageMagick">
<tbody>
<tr valign="top">
<td align="left"><a href="../index.html"><img id="titlebar-west" src="../images/script.png" alt="[ImageMagick]" width="350" height="60" border="0" vspace="28" name="titlebar-west"/></a></td>
<td align="left"><a href="https://secure.networkredux.com/affiliate/idevaffiliate.html?id=146" target="204625385"><img id="titlebar-west" src="../images/networkredux.png" alt="[sponsor]" border="0" vspace="45" name="titlebar-west"/></a></td>
<td width="99%"><br /> </td>
<td style="background-color: white" align="right"><a href="../index.html"><img src="../images/sprite.jpg" alt="" width="114" height="118" border="0" name="titlebar-east"/></a></td>
<td style="background-color: white" align="right"><a href="http://www.imagemagick.org/discourse-server/" target="1850784233"><img id="titlebar-east" src="../images/logo.jpg" alt="" width="114" height="118" border="0" name="titlebar-east"/></a></td>
</tr>
</tbody>
</table>
<table style="width: 100%" border="0" cellpadding="0" cellspacing="0" summary="">
<tbody>
<tr valign="top" style="height: 100%;">
<td id="menu" width="1%" height="100%">
<p><a href="#main">Skip to page contents</a></p>
<font size="-1">
<span>[</span>
<a href="../index.html">About ImageMagick</a>
<span>]</span><br /><span>[</span>
<a href="../www/command-line-tools.html">Command-line Tools</a>
<a href="../www/command-line-processing.html" class="sub">Processing</a>
<a href="../www/command-line-options.html" class="sub">Options</a>
<a href="http://www.imagemagick.org/Usage/" target="1193832166" class="sub">Usage</a>
<a href="../www/api.html">Program Interfaces</a>
<a href="../www/magick-wand.html" class="sub">MagickWand</a>
<a href="../www/magick-core.html" class="sub">MagickCore</a>
<a href="../www/perl-magick.html" class="sub">PerlMagick</a>
<a href="../Magick++/" target="143610407" class="sub">Magick++</a>
<a href="../www/architecture.html">Architecture</a>
<span>]</span><br /><span>[</span>
<a href="../www/install-source.html">Install from Source</a>
<a href="../www/install-source.html#unix" class="sub">Unix</a>
<a href="../www/install-source.html#windows" class="sub">Windows</a>
<a href="../www/binary-releases.html">Binary Releases</a>
<a href="../www/binary-releases.html#unix" class="sub">Unix</a>
<a href="../www/binary-releases.html#macosx" class="sub">Mac OS X</a>
<a href="../www/binary-releases.html#windows" class="sub">Windows</a>
<a href="../www/resources.html">Resources</a>
<span>]</span><br /><span>[</span>
<a href="../www/download.html">Download</a>
<span>]</span><br /><span>[</span>
<a href="../www/sitemap.html">Site Map</a>
<a href="../www/links.html" class="sub">Links</a>
<span>]</span><br /><span>[</span>
<a href="../www/sponsors.html">Sponsors:</a>
<fieldset>
<a href="http://www.testfreaks.com" class="sponsor" target="sponsor">Digital Cameras</a><!-- 200803010000 -->
<br />
<a href="http://business-directory.com"><img src="../images/business+directory.gif" alt="[Business + Directory]" width="105" height="60" border="0" name="business+directory"/></a> <!-- 200808010160 -->
<br />
<a href="http://analogik.com"><img src="../images/analogik.png" alt="[Electronic Music]" width="105" height="60" border="0" name="analogik"/></a> <!-- 200804030160 -->
</fieldset>
<span>]</span>
</font>
</td>
<td id="main" valign="top">
<p class="navigation-index">[<a href="#intro">Introduction to High Dynamic-Range Images</a> • <a href="#enable">Enabling HDRI in ImageMagick</a>]</p>
<div style="margin: auto;">
<h2><a name="intro"></a>Introduction to High Dynamic-Range Images</h2>
</div>
<p>High dynamic-range imaging (HDRI) permits a far greater dynamic range of exposures (i.e. a large difference between light and dark areas) than standard digital imaging techniques. HDRI accurately represents the wide range of intensity levels found in real scenes ranging from the brightest direct sunlight to the deepest darkest shadows. The HDR imaging approach includes:</p>
<ul>
<li>render/capture floating-point color space</li>
<li>encompass the entire perceivable gamut (extend values outside [0,1] range)</li>
<li>post-process in extended color space</li>
<li>apply tone-mapping for specific display</li>
</ul>
<div style="margin: auto;">
<h2><a name="enable"></a>Enabling HDRI in ImageMagick</h2>
</div>
<p>By default image pixels in ImageMagick are stored as unsigned values that range from 0 to the quantum depth which is typically 16-bits (Q16). With HDRI enabled, the pixels are stored in a floating-point representation and can include negative values as well as values that exceed the quantum depth. A majority of digital image formats do not support HDRI so any pixels outside the quantum range are clamped before they are stored. The mostly promising HDR image format is EXR. You will need the <a href="http://www.openexr.org" target="1423672807">OpenEXR</a> delegate library to read or write this format. Other HDR formats include TIFF 48-bit integer and 96-bit float formats, HDR, PFM, and ImageMagick's own MIFF format.<p>
<p>To enable the HDRI version of ImageMagick, use this Unix/Linux command:</p>
<pre class="text">
./configure --enable-hdri
</pre>
<p>Under Windows, set the <kbd>MAGICKCORE_HDRI_SUPPORT</kbd> definition in the <kbd>magick-config.h</kbd> configuration file and build.</p>
<p>To verify HDRI is properly configured, look for "HDRI" in the version string:</p>
<pre class="text">
-> identify -version
Version: ImageMagick 6.3.7 11/01/07 Q16 HDRI http://www.imagemagick.org
</pre>
</td>
<td id="margin" width="1%" height="100%" valign="top" align="right"> </td>
</tr>
</tbody>
</table>
<div id="linkbar">
<a href="http://www.imagemagick.org/discourse-server/" target="820670151">Discourse Server</a> •
<a href="../www/mailing-list.html">Mailing Lists</a> •
<a href="http://www.imagemagick.org/MagickStudio/scripts/MagickStudio.cgi" target="1663193652">ImageMagick Studio</a>
</div>
<div id="footer">
<span id="footer-west">© 1999-2008 ImageMagick Studio LLC</span>
</div>
<div style="clear: both; margin: 0; width: 100%; "></div>
</body>
</html>
