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    <h3><img alt="" src="../sun.gif" align="middle" height="98"
        width="100"> Binning</h3>
    <blockquote>
      <p>To create an image from a FITS Bin Table, the user needs to
        specify a binning factor, binning buffer size, and the binning
        function.<br>
      </p>
      <p>The Binning (or Block) Factor is defined as the following: A
        value greater or equal to zero. This value indicates the number
        of pixel values that will fall into a particular bin.<br>
      </p>
      <p>The Bin Buffer Size is overall size of the image generated.
        This has no relation to min and max values of the columns used
        to create the image. <br>
      </p>
      <p>The Bin Function is defined as the following: Average - all
        pixel values that fall into one pixel bin are averaged. Sum -
        all pixel values that fall into one pixel bin are summed.<br>
      </p>
      <p>Bin to Fit Frame will calculate a bin block factor as a power
        of 2 that will allow the entire data space to be displayed in
        the current frame. </p>
      <p>By default, DS9 will bin about the center of the image. To
        determine the center of the image, DS9 will look for the
        following keywords in order:</p>
      <blockquote> <tt>TDMIN/TDMAX<br>
          TLMIN/TLMAX<br>
          TALEN<br>
          AXLEN</tt> </blockquote>
      <p>If no valid keywords are found, DS9 will define the center as
        the middle of the possible data space based on the coordinate
        data type.</p>
      <br>
      <p><br>
      </p>
      <blockquote> </blockquote>
      <p><br>
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      <br>
    </blockquote>
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