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    <h6 id="header">RMagick 6.1.1 User's Guide and Reference</h6>

    <div class="nav">&laquo;&nbsp;<a href="draw.html">Prev</a> | <a href="index.html">Contents</a> | <a href="info.html">Next</a>&nbsp;&raquo;</div>

    <h1>Miscellaneous classes</h1>

    <div id="toc">
      <h2>Table of Contents</h2>

      <h3><a href="#view">The Image::View class</a></h3>

      <ul>
        <li><a href="#view">Image::View</a></li>
      </ul>

      <h3><a href="#Geometry">The Geometry class</a></h3>

      <ul>
        <li><a href="#Geometry">Geometry</a></li>
      </ul>

      <h3><a href="#Pixel">The Pixel class</a></h3>

      <ul>
        <li><a href="#Pixel">Pixel</a></li>
      </ul>

      <h3><a href="#struct">Struct classes</a></h3>

      <ul>
        <li><a href="#AffineMatrix">AffineMatrix</a></li>

        <li><a href="#Chromaticity">Chromaticity</a></li>

        <li><a href="#Pixel">Pixel</a></li>

        <li><a href="#Point">Point</a></li>

        <li><a href="#Primary">Primary</a></li>

        <li><a href="#Rectangle">Rectangle</a></li>

        <li><a href="#Segment">Segment</a></li>
      </ul>

      <h3><a href="#fill">Fill classes</a></h3>

      <ul>
        <li><a href="#GradientFill">GradientFill</a></li>

        <li><a href="#HatchFill">HatchFill</a></li>

        <li><a href="#SolidFill">SolidFill</a></li>

        <li><a href="#TextureFill">TextureFill</a></li>
      </ul>

      <h3><a href="#exception">Exception classes</a></h3>

      <ul>
        <li><a href="#MagickError">ImageMagickError</a></li>

        <li><a href="#FatalImageMagickError">FatalImageMagickError</a></li>

        <li><a href="#DestroyedImageError">DestroyedImageError</a></li>
      </ul>
    </div>

    <div class="subhd">
      <h2 id="view">The Image::View class</h2>

      <div class="intro">
        <h3>Introduction</h3>

        <p>
          A view is a rectangle in an image. Within the view pixels can be addressed by specifying their <code>[i][j]</code> coordinates. The
          <span class="arg">i</span>, <span class="arg">j</span> index values can identify a single pixel or multiple pixels. Pixels can be accessed or modified
          individually or collectively. Pixel <em>channels</em> (that is, the red, green, blue, and opacity components) can be accessed or modified individually
          or collectively. The <a href="#view_sync">sync</a> method stores modified pixels back into the image.
        </p>
      </div>

      <h3>class Image::View <span class="superclass">&lt; Object</span></h3>

      <div class="sig">
        <h4>new</h4>

        <p>
          Image::View.new(<span class="arg">img</span>, <span class="arg">x</span>, <span class="arg">y</span>, <span class="arg">width</span>,
          <span class="arg">height</span>) -&gt;
          <em>view</em>
        </p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>
          The easiest way to use an <code>Image::View</code> object is to create it with the <a href="image3.html#view">Image#view</a> method, which provides a
          block-scoped view and automatic syncing. You probably won't want to create a view by calling <code>new</code>.
        </p>

        <h5>Arguments</h5>

        <dl>
          <dt>img</dt>

          <dd>The image from which the view is taken.</dd>

          <dt>x, y</dt>

          <dd>
            The x- and y-offsets of the view relative to the top-left corner of the image. Within the view, pixel addresses are relative to the top-left corner
            of the view.
          </dd>

          <dt>width, height</dt>

          <dd>The number of columns and the number of rows in the view.</dd>
        </dl>

        <p>It is an error to specify a view that exceeds the boundaries of the image.</p>
      </div>

      <div class="sig">
        <h4>[][]</h4>

        <p><span class="arg">view</span>[<span class="arg">i</span>][<span class="arg">j</span>] -&gt; <em>pixel</em> or <em>array</em></p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>
          Return one or more pixels in the view. If i and j are each a single integer value, returns a single pixel. For any other indexes, returns an array of
          one or more pixels. If any index exceeds the boundaries of the view, raises <code>IndexError</code>.
        </p>

        <h5>Arguments</h5>

        <p>
          The <span class="arg">i</span> index identifies a set of rows in the view. The <span class="arg">j</span> index identifies a set of columns in the
          view. The pixels that are returned are the intersection of these two sets. The indexes can be:
        </p>

        <dl>
          <dt>omitted</dt>

          <dd>If <span class="arg">i</span> is omitted, all the rows are used. If <code>j</code> is omitted, all the columns are used.</dd>

          <dt>an integer</dt>

          <dd>
            or an object that can be converted to an integer. A single integer identifies a single row or column. Identify a single pixel by specifying integers
            for both indexes. If the index is negative, counts from the bottom row or right column of the view.
          </dd>

          <dt>start, length</dt>

          <dd>
            Identifies the set of <code>length</code> rows or columns starting with <code>start</code>. If <code>start</code> is negative, starts at the bottom
            row or right column of the view.
          </dd>

          <dt>an object that responds to <code>each</code></dt>

          <dd>
            The index may be any object that responds to <code>each</code> by returning a sequence of objects that can be converted to integers. An array with
            integer values or a range of integers are two examples.
          </dd>
        </dl>

        <h5>Examples</h5>
        <pre class="language-ruby">
  # Get the 2nd pixel in the 4th row of the view.
  pixel = view[3][1]  # returns a pixel
  # Returns an array with only one value
  pixels = view[[3]][[1]]
  # Get all the pixels in the 4th row
  pixels = view[3][]
  # Use arrays to specify a non-contiguous set of rows and columns
  pixels = view[[1,3,5]][[2,4,6]]
  # Use ranges to specify a contiguous set of rows and columns
  pixels = view[1..5][2..6]
</pre
        >
      </div>

      <div class="sig">
        <h4>
          [][].red<br />
          [][].green<br />
          [][].blue<br />
          [][].opacity
        </h4>

        <p>
          [<span class="arg">i</span>][<span class="arg">j</span>].red -&gt; <em>integer</em> or <em>array</em><br />
          [<span class="arg">i</span>][<span class="arg">j</span>].green -&gt; <em>integer</em> or <em>array</em><br />
          [<span class="arg">i</span>][<span class="arg">j</span>].blue -&gt; <em>integer</em> or <em>array</em><br />
          [<span class="arg">i</span>][<span class="arg">j</span>].opacity -&gt; <em>integer</em> or <em>array</em>
        </p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>
          If the indexes identify a single pixel, these methods return the value of the red, green, blue, or opacity channel of that pixel. If the indexes
          identify more than one pixel, these methods return an array of values. See <code>[][]</code> for a description of possible index arguments.
        </p>

        <h5>Examples</h5>
        <pre class="language-ruby">
  # Get the value of the green channel of
  # the top-left pixel in the view.
  view[0][0] = Magick::Pixel.new(0,128,255)
  g = view[0][0].green  # returns 128

  # Get the maximum value of the red channel
  # for all the pixels in the top row of the view.
  m = view[0][].red.max
</pre
        >
      </div>

      <div class="sig">
        <h4>[][]=</h4>

        <p><span class="arg">view</span>[<span class="arg">i</span>][<span class="arg">j</span>] = <em>rvalue</em></p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>
          Replaces each pixel identified by the indexes with a duplicate of
          <span class="arg">rvalue</span>. The rvalue is either a <a href="#Pixel">Pixel</a> object or a <a href="imusage.html#color_names">color name</a>. If
          <code>rvalue</code> is a color name, calls <code>Pixel.from_color</code> to create a pixel.
        </p>

        <h5>Arguments</h5>

        <p>The indexes are the same as <code>[][]</code>, above.</p>

        <dl>
          <dt>rvalue</dt>

          <dd>Either a pixel or a color name.</dd>
        </dl>
      </div>

      <div class="sig">
        <h4>
          [][].red=<br />
          [][].green=<br />
          [][].blue=<br />
          [][].opacity=
        </h4>

        <p>
          [<span class="arg">i</span>][<span class="arg">j</span>].red = <em>integer</em><br />
          [<span class="arg">i</span>][<span class="arg">j</span>].green = <em>integer</em><br />
          [<span class="arg">i</span>][<span class="arg">j</span>].blue = <em>integer</em><br />
          [<span class="arg">i</span>][<span class="arg">j</span>].opacity =
          <em>integer</em>
        </p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>Assigns <em>integer</em> to the red, green, blue, or opacity channel of the pixel or pixels identified by the indexes.</p>

        <h5>Examples</h5>
        <pre class="language-ruby">
  # Set the red channel of all the pixels in the 2nd
  # row of the view to QuantumRange
  view[1][].red = Magick::QuantumRange
  # Set the green channel of the pixel at [20][30] to
  # half that of its left-hand neighbor.
  view[20][30].green = view[20][29].green * 0.5
</pre
        >
      </div>

      <div id="view_sync" class="sig">
        <h4>sync</h4>

        <p><span class="arg">view</span>.sync(<span class="arg">force</span>=<code>false</code>) -&gt; <code>true</code> or <code>false</code></p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>
          If any of the pixels in the view have been modified, this method stores them in the image. If no pixels have been modified, this method has no effect.
        </p>

        <h5>Arguments</h5>

        <dl>
          <dt>force</dt>

          <dd>If <code>true</code>, forces the view pixels to be stored in the image even if none have been modified.</dd>
        </dl>

        <h5>Returns</h5>
        Returns <code>true</code> if the pixels were stored in the image either because the <code>dirty</code> flag was <code>true</code> or
        <code>force</code> was <code>true</code>, <code>false</code> otherwise.
      </div>

      <div class="sig">
        <h4>
          dirty<br />
          dirty=
        </h4>

        <p>
          view.dirty -&gt; <code>true</code> or <code>false</code><br />
          view.dirty = <code>true</code> or <code>false</code>
        </p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>
          Any modification to a pixel in the view causes the
          <code>dirty</code> attribute to be set to <code>true</code>. You can (although normally you don't need to) set <code>dirty=true</code> to force
          <code>sync</code> to store the pixels in the image, or set <code>dirty=false</code> to keep <code>sync</code> from storing the pixels.
        </p>
      </div>

      <div class="sig">
        <h4>
          x<br />
          y<br />
          width<br />
          height
        </h4>

        <p>
          x -&gt; integer<br />
          y -&gt; integer<br />
          width -&gt; integer<br />
          height -&gt; integer
        </p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>
          The <span class="arg">x</span>, <span class="arg">y</span>, <span class="arg">width</span>, and <span class="arg">height</span> arguments specified
          when the view was created.
        </p>
      </div>
    </div>

    <div class="subhd" id="Geometry">
      <h2>The Geometry class</h2>

      <div class="intro">
        <h3>Introduction</h3>

        <p>
          The Geometry class contains the same information as an ImageMagick
          <a href="imusage.html#geometry">geometry string</a>. Geometry objects are interchangeable with geometry strings.
        </p>
      </div>

      <h3>class Geometry <span class="superclass">&lt; Object</span></h3>

      <div class="sig">
        <h4>new</h4>

        <p>
          Geometry.new(<span class="arg">width</span>=nil, <span class="arg">height</span>=nil, <span class="arg">x</span>=nil, <span class="arg">y</span>=nil,
          <span class="arg">flag</span>=nil) -&gt; <em>geometry</em>
        </p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>Constructs a new <code>Geometry</code> object.</p>

        <h5>Attributes</h5>

        <p>
          A geometry string has the general form "WxH+x+y[!@%&lt;&gt;]. In a
          <code>Geometry</code> object,
        </p>

        <dl>
          <dt>width</dt>

          <dd>specifies the W value</dd>

          <dt>height</dt>

          <dd>specifies the H value</dd>

          <dt>x, y</dt>

          <dd>specify the x and y values, respectively</dd>

          <dt>flag</dt>

          <dd>one of the constants shown in this table:</dd>
        </dl>

        <table summary="geometry flag constants" class="simple_table">
          <caption>
            <strong>Geometry flag constants</strong>
          </caption>

          <tr>
            <td align="center">
              <strong
                >Constant<br />
                name</strong
              >
            </td>

            <td align="center">
              <strong
                >Geometry<br />
                string flag</strong
              >
            </td>

            <td align="center"><strong>Explanation</strong></td>
          </tr>

          <tr>
            <td valign="top">PercentGeometry</td>

            <td valign="top" align="center">%</td>

            <td>
              Normally the attributes are treated as pixels. Use this flag when the <code>width</code> and <code>height</code> attributes represent
              <em>percentages</em>. For example, 125x75 means 125% of the height and 75% of the width. The <code>x</code> and <code>y</code> attributes are not
              affected by this flag.
            </td>
          </tr>

          <tr>
            <td valign="top">AspectGeometry</td>

            <td valign="top" align="center">!</td>

            <td>
              Use this flag when you want to force the new image to have exactly the size specified by the the <code>width</code> and
              <code>height</code> attributes.
            </td>
          </tr>

          <tr>
            <td valign="top">LessGeometry</td>

            <td valign="top" align="center">&lt;</td>

            <td>
              Use this flag when you want to change the size of the image only if both its width and height are smaller the values specified by those
              attributes. The image size is changed proportionally.
            </td>
          </tr>

          <tr>
            <td valign="top">GreaterGeometry</td>

            <td valign="top" align="center">&gt;</td>

            <td>
              Use this flag when you want to change the size of the image if either its width and height exceed the values specified by those attributes. The
              image size is changed proportionally.
            </td>
          </tr>

          <tr>
            <td valign="top">AreaGeometry</td>

            <td valign="top" align="center">@</td>

            <td>
              This flag is useful only with a single
              <code>width</code> attribute. When present, it means the <code>width</code> attribute represents the total area of the image in pixels.
            </td>
          </tr>

          <tr>
            <td valign="top">MinimumGeometry</td>

            <td valign="top" align="center">^</td>

            <td class="imquote">
              Use ^ to set a minimum image size limit. The geometry 640x480^, for example, means the image width will not be less than 640 and the image height
              will not be less than 480 pixels after the resize. One of those dimensions will match the requested size, but the image will likely overflow the
              space requested to preserve its aspect ratio.
            </td>
          </tr>
        </table>

        <p>If any attribute is omitted the default is nil or 0.</p>

        <h5>Example</h5>
        <pre class="language-ruby">
g = Magick::Geometry.new(100,200,nil,nil,Magick::AspectGeometry)
</pre
        >
      </div>
    </div>

    <div class="sig">
      <h4>from_s</h4>

      <p>Geometry.<span class="arg">from_s</span>(<span class="arg">string</span>) -&gt; <em>geometry</em></p>
    </div>

    <div class="desc">
      <h5>Description</h5>

      <p>Constructs a new <code>Geometry</code> object from a <a href="imusage.html#geometry">geometry string</a>.</p>
    </div>

    <div class="sig">
      <h4>to_s</h4>

      <p><span class="arg">geom.</span>to_s() -&gt; <em>string</em></p>
    </div>

    <div class="desc">
      <h5>Description</h5>

      <p>Returns the string equivalent of the <code>Geometry</code> object..</p>
    </div>

    <div class="subhd" id="Pixel">
      <h2>The Pixel class</h2>

      <div class="intro">
        <h3>Introduction</h3>

        <p>
          A pixel describes the smallest individually addressable part of an image. In the RGB
          <a href="constants.html#ColorspaceType">colorspace</a>, a pixel's color is described by its intensity in the red, green, and blue channels. Its
          opacity is described by its intensity in the opacity (also called alpha, or matte) channel. In the CMYK colorspace a pixel's color is described by its
          intensity in the cyan, magenta, yellow and black (K) channels. Intensity is a value between 0 and
          <a href="constants.html#Miscellaneous_constants">QuantumRange</a>.
        </p>

        <p>
          Usually, RMagick methods operate on entire images or on groups of pixels that have been selected by their position or color. Some methods, such as
          <a href="image3.html#pixel_color">pixel_color</a> and <a href="image3.html#view">view</a>, operate on individual pixels or even on the RGBA (or CMYK)
          components thereof.
        </p>
      </div>

      <h3>
        class Pixel <span class="superclass">&lt; Object</span><br />
        <span class="mixin">mixes in Comparable, Observable</span>
      </h3>

      <div class="sig">
        <h4>new</h4>

        <p>
          Pixel.new(<span class="arg">red</span>, <span class="arg">green</span>, <span class="arg">blue</span>, <span class="arg">opacity</span>) -&gt;
          <em>pixel</em>
        </p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>
          Constructs a pixel object from the specified red, green, blue, and opacity intensities. The intensity is a number between 0 and
          <a href="constants.html#Miscellaneous_constants">QuantumRange</a>.
        </p>

        <h5>Attributes</h5>

        <dl>
          <dt>red, green, blue</dt>

          <dd>
            The red, green, and blue intensities of the pixel, respectively. If the colorspace is
            <a href="constants.html#ColorspaceType">CMYKColorspace</a>, these attributes are interpreted as the cyan, magenta, and yellow intensities.
          </dd>

          <dt>opacity</dt>

          <dd>
            The opacity level. Higher intensities are more transparent. If the colorspace is CMYKColorspace, this attribute is interpreted as the black
            intensity.
          </dd>

          <dt>cyan, magenta, yellow, black</dt>

          <dd>These attributes are aliases for <code>red</code>, <code>green</code>, <code>blue</code>, and <code>opacity</code>, respectively.</dd>
        </dl>
      </div>

      <div class="sig">
        <h4>from_color</h4>

        <p>
          Pixel.from_color(<span class="arg">color_name</span>) -&gt;
          <em>pixel</em>
        </p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>
          Constructs a new Pixel object from the
          <a href="imusage.html#color_names">color name</a>. Raises ArgumentError if the name is unknown.
        </p>
      </div>

      <div class="sig">
        <h4 id="from_hsla">from_hsla</h4>

        <p>
          Pixel.from_hsla(<span class="arg">hue</span>, <span class="arg">saturation</span>, <span class="arg">lightness</span>,
          <span class="arg">alpha</span>=1.0) -&gt; <em>pixel</em>
        </p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>Constructs a pixel object from the specified arguments.</p>

        <h5>Arguments</h5>

        <dl>
          <dt>hue</dt>

          <dd>Either a String percentage (e.g., "25%") or a value in the range [0.0, 360.0).</dd>

          <dt>saturation</dt>

          <dd>Either a String percentage (e.g., "25%") or a value in the range [0.0, 255.0].</dd>

          <dt>lightness</dt>

          <dd>Either a String percentage (e.g., "25%") or a value in the range [0.0, 255.0].</dd>

          <dt>alpha</dt>

          <dd>
            Either a String percentage (e.g., "25%") or a value in the range [0.0, 1.0], where 1.0 is fully opaque and 0.0 is fully transparent. This argument
            may be omitted. The default is 1.0.
          </dd>
        </dl>

        <h5>See also</h5>

        <p><a href="#to_hsla">to_hsla</a></p>
      </div>

      <div class="sig">
        <h4 id="spaceship">&lt;=&gt;</h4>

        <p><span class="arg">pixel1</span> &lt;=&gt; <span class="arg">pixel2</span> -&gt; -1, 0, <em>or</em> 1</p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>Returns -1, 0, or 1 depending on if <span class="arg">pixel1</span> is "less than," equal, or "greater than" the <span class="arg">pixel2</span>.</p>

        <p>
          Since there is no way to rank order pixels, and thus determine if one pixel is "greater than" or "less than" another, this method uses an arbitrary
          algorithm that ensures these two conditions:
        </p>

        <ol>
          <li>pixels with equal RGBA (or CMYK) values compare equal, and</li>

          <li>comparing the same two unequal pixels always returns the same result.</li>
        </ol>

        <h5>Returns</h5>

        <p>-1, 0, or 1</p>

        <h5>See also</h5>

        <p><a href="#fcmp">fcmp</a></p>
      </div>

      <div class="sig">
        <h4 id="fcmp">fcmp</h4>

        <p>
          <span class="arg">pixel</span>.fcmp(<span class="arg">pixel</span>, <span class="arg">fuzz</span>=0.0,
          <span class="arg">colorspace</span>=RGBColorspace) -&gt; <code>true</code> <em>or</em> <code>false</code>
        </p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>
          Returns true if the argument is the same color as
          <span class="arg">pixel</span>.
        </p>

        <h5>Arguments</h5>

        <dl>
          <dt>pixel</dt>

          <dd>The pixel to which the receiver is compared.</dd>

          <dt>fuzz</dt>

          <dd>The amount of fuzz to allow before the colors are considered to be different.</dd>

          <dt>colorspace</dt>

          <dd>
            If the pixels are in the CMYK colorspace, specify
            <a href="constants.html#ColorspaceType">Magick::CMYKColorspace</a>.
          </dd>
        </dl>

        <h5>Returns</h5>

        <p><code>true</code> or <code>false</code></p>

        <h5>See also</h5>

        <p><a href="#spaceship">&lt;=&gt;</a></p>
      </div>

      <div class="sig">
        <h4>intensity</h4>

        <p><span class="arg">pixel</span>.intensity() -&gt; integer</p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>Returns the intensity of the pixel. The intensity is computed as 0.299*R+0.587*G+0.114*B.</p>
      </div>

      <div class="sig">
        <h4>to_color</h4>

        <p>
          <span class="arg">pixel</span>.to_color(<span class="arg">compliance</span>=AllCompliance, <span class="arg">matte</span>=<code>false</code>,
          <span class="arg">depth</span>=<code>QuantumDepth</code>, <span class="arg">hex</span>=<code>true</code>) -&gt; <em>string</em>
        </p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>
          Returns the
          <a href="imusage.html#color_names">color name</a> corresponding the the pixel values. If there is no such named color in the specified color standard,
          returns a string in the form "rgb(r,g,b,a)".
        </p>

        <h5>Arguments</h5>

        <dl>
          <dt>compliance</dt>

          <dd>
            A <a href="constants.html#ComplianceType">ComplianceType</a>
            constant. The default value of AllCompliance causes
            <code>to_color</code> to search for a color name in any of the 3 defined color standards.
          </dd>

          <dt>matte</dt>

          <dd>If false, the pixel's opacity attribute is ignored.</dd>

          <dt>depth</dt>

          <dd>
            An image depth. The default is the quantum depth used when ImageMagick was compiled. The values 16 and 32 can be used only when ImageMagick was
            compiled with the appropriate QuantumDepth.
          </dd>

          <dt>hex</dt>

          <dd>
            If true, represent the color name in hex (#rrggbbaa or #rrrrggggbbbbaaaa) format. In this case
            <span class="arg">compliance</span> is meaningless.
          </dd>
        </dl>

        <h5>See also</h5>

        <p>
          Compare this method to
          <a href="image3.html#to_color">Image#to_color</a>, in which the <span class="arg">matte</span> and <span class="arg">depth</span> values are taken
          from an image.
        </p>
      </div>

      <div class="sig">
        <h4 id="to_hsla">to_hsla</h4>

        <p><span class="arg">pixel</span>.to_HSL -&gt; <em>array</em></p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>Converts the RGB representation of the pixel to hue, saturation, lightness, and alpha values.</p>

        <h5>Returns</h5>

        <p>
          An array of the form <code>[hue, saturation, lightness, alpha]</code>. Each value is in the range specified for it, as described in
          <a href="#from_hsla">from_hsla</a>, above.
        </p>
      </div>
    </div>

    <div class="subhd">
      <h2 id="struct">Struct classes</h2>

      <div class="intro">
        <h3>Introduction</h3>

        <p>
          These classes are created by the Struct class and are used to create objects used as attribute and argument values in other RMagick classes. Like all
          the classes created by Struct, these classes define both getter and setter methods for their attributes. That is, for an attribute <em>x</em> both the
          <code>x</code> and <code>x=</code> methods are defined.
        </p>

        <p>The <code>Pixel</code> and <code>Geometry</code> classes define additional constructors and conversion methods.</p>
      </div>

      <h3 id="AffineMatrix">class AffineMatrix <span class="superclass">&lt; Struct</span></h3>

      <div class="sig">
        <h4>new</h4>

        <p>
          AffineMatrix.new(<span class="arg">sx</span>, <span class="arg">rx</span>, <span class="arg">ry</span>, <span class="arg">sy</span>,
          <span class="arg">tx</span>, <span class="arg">ty</span>) -&gt; <em>matrix</em>
        </p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>
          An AffineMatrix object describes a coordinate transformation. This object is used as an argument to the
          <a href="image1.html#affine_transform">Image#affine_transform</a>, <a href="image1.html#composite_affine">Image#composite_affine</a>, and
          <a href="draw.html#affine_eq">Draw#affine</a> methods.
        </p>

        <h5>Attributes</h5>

        <dl>
          <dt>sx, sy</dt>

          <dd>The amount of scaling on the x- and y- axes.</dd>

          <dt>rx, ry</dt>

          <dd>The amount of rotation on the x- and y-axes, in radians.</dd>

          <dt>tx, ty</dt>

          <dd>The amount of translation on the x- and y-axes, in pixels.</dd>
        </dl>
      </div>

      <h3 id="Chromaticity">class Chromaticity <span class="superclass">&lt; Struct</span></h3>

      <div class="sig">
        <h4>new</h4>

        <p>
          Chromaticity.new(<span class="arg">red_primary</span>, <span class="arg">green_primary</span>, <span class="arg">blue_primary</span>,
          <span class="arg">white_point</span>) -&gt; <em>chromaticity</em>
        </p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>
          A Chromaticity object represents chromaticity values for the
          <a href="imageattrs.html#chromaticity">Image#chromaticity</a>
          attribute.
        </p>

        <h5>Attributes</h5>

        <p>The attribute values are <a href="#Primary">Primary</a> objects.</p>

        <dl>
          <dt>red_primary</dt>

          <dd>Red primary point (e.g. red_primary.x=0.64, red_primary.y=0.33)</dd>

          <dt>green_primary</dt>

          <dd>Green primary point (e.g. green_primary.x=0.3, green_primary.y=0.6)</dd>

          <dt>blue_primary</dt>

          <dd>Blue primary point (e.g. blue_primary.x=0.15, blue_primary.y=0.06)</dd>

          <dt>white_point</dt>

          <dd>White point (e.g. white_point.x=0.3127, white_point.y=0.329)</dd>
        </dl>
      </div>

      <h3 id="Point">class Point <span class="superclass">&lt; Struct</span></h3>

      <div class="sig">
        <h4>new</h4>

        <p>Point.new(<span class="arg">x</span>, <span class="arg">y</span>) -&gt; <em>point</em></p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>
          The value of the <code>pixels_per_em</code> attribute in the TypeMetric struct returned by
          <a href="draw.html#get_type_metrics">Draw#get_type_metrics</a> is a <code>Point</code> object..
        </p>

        <h5>Attributes</h5>

        <dl>
          <dt>x</dt>

          <dd>Character width</dd>

          <dt>y</dt>

          <dd>Character height</dd>
        </dl>
      </div>

      <h3 id="Primary">class Primary <span class="superclass">&lt; Struct</span></h3>

      <div class="sig">
        <h4>new</h4>

        <p>Primary.new(<span class="arg">x</span>, <span class="arg">y</span>, <span class="arg">z</span>) -&gt; <em>primary</em></p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>See <a href="#Chromaticity">Chromaticity</a> class.</p>

        <h5>Attributes</h5>

        <dl>
          <dt>x</dt>

          <dd>X ordinate</dd>

          <dt>y</dt>

          <dd>Y ordinate</dd>

          <dt>z</dt>

          <dd>Z ordinate. This attribute is always ignored.</dd>
        </dl>
      </div>

      <h3 id="Rectangle">class Rectangle <span class="superclass">&lt; Struct</span></h3>

      <div class="sig">
        <h4>new</h4>

        <p>
          Rectangle.new(<span class="arg">width</span>, <span class="arg">height</span>, <span class="arg">x</span>, <span class="arg">y</span>) -&gt;
          <em>rectangle</em>
        </p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>
          The value of the
          <a href="imageattrs.html#bounding_box">Image#bounding_box</a>
          attributes.
        </p>

        <h5>Attributes</h5>

        <dl>
          <dt>width</dt>

          <dd>Rectangle width</dd>

          <dt>height</dt>

          <dd>Rectangle height</dd>

          <dt>x</dt>

          <dd>Offset from the left edge of the image</dd>

          <dt>y</dt>

          <dd>Offset from the top edge of the image</dd>
        </dl>
      </div>

      <h3 id="Segment">class Segment <span class="superclass">&lt; Struct</span></h3>

      <div class="sig">
        <h4>new</h4>

        <p>
          Segment.new(<span class="arg">x1</span>, <span class="arg">y1</span>, <span class="arg">x2</span>, <span class="arg">y2</span>) -&gt;
          <em>segment</em>
        </p>
      </div>

      <div class="desc">
        <h5>Description</h5>

        <p>
          The value of the <code>bounds</code> attribute in the
          <a href="draw.html#get_type_metrics">TypeMetric</a>
          class.
        </p>

        <h5>Attributes</h5>

        <p><em>x1</em>, <em>y1</em>, <em>x2</em>, <em>y2</em></p>
      </div>
    </div>

    <div class="subhd">
      <h2 id="fill">Fill classes</h2>
    </div>

    <div class="intro">
      <h3>Introduction</h3>

      <p>
        The <a href="image1.html#new">Image#new</a> and <a href="ilist.html#new_image">ImageList#new_image</a> methods accept a <code>Fill</code> object as an
        optional third argument. A <code>Fill</code> object is an instance of a <em>Fill class</em>. Fill classes are designed to support custom background
        fills. Each <code>Fill</code> class defines only two methods, <code>initialize</code> and <code>fill</code>. The <code>initialize</code> method is
        called from the application to create an instance of the fill class. It accepts any arguments and does whatever is necessary to create the fill. The
        <code>fill</code> method is called from the initialize method of the new image object, after the image is completely initialized. The
        <code>fill</code> method gets the image as its only argument and sends whatever methods are necessary to the image to fill the image's background.
      </p>

      <p>
        RMagick supplies three Fill classes,
        <code><strong>HatchFill</strong></code
        >, <code><strong>GradientFill</strong></code
        >, <code><strong>SolidFill</strong></code> and <code><strong>TextureFill</strong></code
        >. These classes are explained below. The <code>HatchFill</code> class is intended as an example of how to write a <code>Fill</code> class and is
        written in pure Ruby. You can read it in rmagick_internal.rb.
      </p>
    </div>

    <h3 id="GradientFill">class GradientFill <span class="superclass">&lt; Object</span></h3>

    <div class="sig">
      <h4>new</h4>

      <p>
        GradientFill.new(<span class="arg">x1</span>, <span class="arg">y1</span>, <span class="arg">x2</span>, <span class="arg">y2</span>,
        <span class="arg">start_color</span>, <span class="arg">end_color</span>) -&gt; <em>gradient_fill</em>
      </p>
    </div>

    <div class="desc">
      <h5>Description</h5>

      <p>
        Creates a gradient fill. The <span class="arg">x1</span>, <span class="arg">y1</span>, and <span class="arg">x2</span>,
        <span class="arg">y2</span> arguments describe either a line or a point. If <span class="arg">x1</span> != <span class="arg">x2</span> or
        <span class="arg">y1</span> != <span class="arg">y2</span>, then the arguments describe the starting line for the gradient. The gradient will start with
        <span class="arg">start_color</span> at the starting line and gradually transform to <span class="arg">end_color</span> as the distance increases from
        the starting line.
      </p>

      <p>
        If <span class="arg">x1</span> == <span class="arg">x2</span> and <span class="arg">y1</span> == <span class="arg">y2</span>, the gradient radiates from
        the specified point, gradually transforming from <span class="arg">start_color</span> to <span class="arg">end_color</span>.
      </p>

      <p>The line or point does not have to lie within the image bounds.</p>

      <h5>Arguments</h5>

      <dl>
        <dt>x1, y1</dt>

        <dd>One of the starting line end-points.</dd>

        <dt>x2, y2</dt>

        <dd>The other end-point on the starting line.</dd>

        <dt>start_color</dt>

        <dd>The color at the starting line.</dd>

        <dt>end_color</dt>

        <dd>The color to which the gradient transforms.</dd>
      </dl>

      <h5>Example</h5>

      <p>
        <a href="javascript:popup('gradientfill.rb.html')"
          ><img src="ex/gradientfill.gif" alt="GradientFill example" title="Click to see the example script"
        /></a>
      </p>
    </div>

    <h3 id="HatchFill">class HatchFill <span class="superclass">&lt; Object</span></h3>

    <div class="sig">
      <h4>new</h4>

      <p>
        HatchFill.new(<span class="arg">background_color</span>, <span class="arg">hatch_color</span>='white', <span class="arg">dist</span>=10) -&gt;
        <em>hatch_fill</em>
      </p>
    </div>

    <div class="desc">
      <h4>Description</h4>

      <p>Creates a cross-hatched fill.</p>

      <h4>Arguments</h4>

      <dl>
        <dt>background_color</dt>

        <dd>The image background color.</dd>

        <dt>hatch_color</dt>

        <dd>The color of the cross-hatch lines.</dd>

        <dt>dist</dt>

        <dd>The distance between cross-hatch lines, in pixels.</dd>
      </dl>

      <h4>Example</h4>

      <p>
        <a href="javascript:popup('hatchfill.rb.html')"><img src="ex/hatchfill.gif" alt="HatchFill example" title="Click to see the example script" /></a>
      </p>
    </div>

    <h3 id="SolidFill">class SolidFill <span class="superclass">&lt; Object</span></h3>

    <div class="sig">
      <h4>new</h4>

      <p>
        SolidFill.new(<span class="arg">bgcolor</span>) -&gt;
        <em>solid_fill</em>
      </p>
    </div>

    <div class="desc">
      <h5>Description</h5>

      <p>Creates a solid fill.</p>

      <h5>Arguments</h5>

      <dl>
        <dt>bgcolor</dt>

        <dd>The image background color.</dd>
      </dl>

      <h5>Example</h5>

      <p>
        <a href="javascript:popup('solidfill.rb.html')"><img src="ex/solidfill.gif" alt="SolidFill example" title="Click to see the example script" /></a>
      </p>
    </div>

    <h3 id="TextureFill">class TextureFill <span class="superclass">&lt; Object</span></h3>

    <div class="sig">
      <h4>new</h4>

      <p>
        TextureFill.new(<span class="arg">texture_image</span>) -&gt;
        <em>texture_fill</em>
      </p>
    </div>

    <div class="desc">
      <h5>Description</h5>

      <p>
        Creates a texture fill by tiling the
        <span class="arg">texture_image</span> to fill the image.
      </p>

      <h5>Arguments</h5>

      <p>
        The texture to be used as the background. May be an image or imagelist. If <span class="arg">texture_image</span> is an imagelist, uses the current
        image.
      </p>

      <h5>Example</h5>

      <p>
        <a href="javascript:popup('texturefill.rb.html')"><img src="ex/texturefill.gif" alt="TextureFill example" title="Click to see the example script" /></a>
      </p>
    </div>

    <div class="subhd">
      <h2 id="exception">Exception classes</h2>

      <h3 id="MagickError">
        class ImageMagickError
        <span class="superclass">&lt; StandardError</span>
      </h3>

      <div class="desc">
        <h4>Description</h4>

        <p>RMagick raises this exception when an ImageMagick function returns an error condition.</p>
      </div>

      <h3 id="FatalImageMagickError">
        class FatalImageMagickError
        <span class="superclass">&lt; StandardError</span>
      </h3>

      <div class="desc">
        <h4>Description</h4>

        <p>RMagick raises this exception when ImageMagick raises a fatal (unrecoverable) error condition.</p>
      </div>

      <h3 id="DestroyedImageError">
        class DestroyedImageError
        <span class="superclass">&lt; StandardError</span>
      </h3>

      <div class="desc">
        <h4>Description</h4>

        <p>
          RMagick raises this exception when any Image method (except
          <a href="image1.html#destroyed_q">destroyed?</a> and <a href="image2.html#inspect">inspect</a>) is called after an image has been
          <a href="image1.html#destroy_bang">destroyed</a>.
        </p>
      </div>
    </div>

    <p class="spacer">&nbsp;</p>

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