<?xml version="1.0" encoding="utf-8" ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <meta name="generator" content="Docutils 0.13.1: http://docutils.sourceforge.net/" /> <title>Magick::Image Data Structures</title> <link rel="stylesheet" href="../docutils-articles.css" type="text/css" /> </head> <body> <div class="banner"> <img src="../images/gm-107x76.png" alt="GraphicMagick logo" width="107" height="76" /> <span class="title">GraphicsMagick</span> <form action="http://www.google.com/search"> <input type="hidden" name="domains" value="www.graphicsmagick.org" /> <input type="hidden" name="sitesearch" value="www.graphicsmagick.org" /> <span class="nowrap"><input type="text" name="q" size="25" maxlength="255" /> <input type="submit" name="sa" value="Search" /></span> </form> </div> <div class="navmenu"> <ul> <li><a href="../index.html">Home</a></li> <li><a href="../project.html">Project</a></li> <li><a href="../download.html">Download</a></li> <li><a href="../README.html">Install</a></li> <li><a href="../Hg.html">Source</a></li> <li><a href="../NEWS.html">News</a> </li> <li><a href="../utilities.html">Utilities</a></li> <li><a href="../programming.html">Programming</a></li> <li><a href="../reference.html">Reference</a></li> </ul> </div> <div class="document" id="magick-image-data-structures"> <h1 class="title">Magick::Image Data Structures</h1> <!-- -*- mode: rst -*- --> <!-- This text is in reStucturedText format, so it may look a bit odd. --> <!-- See http://docutils.sourceforge.net/rst.html for details. --> <p>The class Magick::Image is a simple handle which points to a reference-counted image representation. This allows multiple Magick::Image instances to share the same image and attributes. At the point in time that the image data, or image attributes are modified and the current reference count is greater than one, the image data and attributes are copied to create a new image with a reference count of one and the reference count on the old image is decremented. If the reference count on the old image becomes zero, then the associated reference and data are deleted. This strategy represents a simple (but effective) form of garbage collection.</p> <img alt="Figure showing Image class design" src="Image.png" style="width: 910px; height: 490px;" /> <p>Copyright © Bob Friesenhahn 1999 - 2017</p> </div> </body> </html>