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  6.     <title>10.18.¬† Layer Color-Stretching Commands</title>
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  14.     <link rel="prev" href="gimp-layer-reverse.html" title="10.17.¬† The ‚ÄúReverse Layer Order‚Äù command" />
  15.     <link rel="next" href="plug-in-autocrop.html" title="10.19.¬† Autocrop Layer" />
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  17.   <body>
  18.     <div class="navheader">
  19.       <table width="100%" summary="Navigation header">
  20.         <tr>
  21.           <th colspan="3" align="center">10.18.¬†
  22.     <span lang="en" xml:lang="en">Layer Color-Stretching Commands</span>
  23.   </th>
  24.         </tr>
  25.         <tr>
  26.           <td width="20%" align="left"><a accesskey="p" href="gimp-layer-reverse.html"><img src="../images/prev.png" alt="Prev" /></a>¬†</td>
  27.           <th width="60%" align="center">10.¬†
  28.     <span lang="en" xml:lang="en">The ‚Äú<span class="quote">Layers</span>‚Äù Menu</span>
  29.   </th>
  30.           <td width="20%" align="right">¬†<a accesskey="n" href="plug-in-autocrop.html"><img src="../images/next.png" alt="Next" /></a></td>
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  35.     <div class="sect2" lang="en" xml:lang="en">
  36.       <div class="titlepage">
  37.         <div>
  38.           <div>
  39.             <h3 class="title"><a id="gimp-layer-stretch-commands"></a>10.18.¬†
  40.     <span lang="en" xml:lang="en">Layer Color-Stretching Commands</span>
  41.   </h3>
  42.           </div>
  43.           <div>
  44.             <div class="revhistory">
  45.               <table border="1" width="100%" summary="Revision history">
  46.                 <tr>
  47.                   <th align="left" valign="top" colspan="3">
  48.                     <b>Revision History</b>
  49.                   </th>
  50.                 </tr>
  51.                 <tr>
  52.                   <td align="left">Revision $Revision: 2412 $</td>
  53.                   <td align="left">2006-09-11</td>
  54.                   <td align="left">scb</td>
  55.                 </tr>
  56.               </table>
  57.             </div>
  58.           </div>
  59.         </div>
  60.       </div>
  61.       <a id="id2707300" class="indexterm"></a>
  62.       <a id="id2707318" class="indexterm"></a>
  63.       <p>
  64.     <acronym class="acronym">GIMP</acronym> has several automatic commands for stretching
  65.     the columns of the histogram for the color channels of the active
  66.     layer. By pushing bright pixels to the right and dark pixels to the
  67.     left, they make bright pixels brighter and dark pixels darker, which
  68.     enhances the contrast in the layer.
  69.   </p>
  70.       <p>
  71.     Some of the commands stretch the three color channels equally, so that the
  72.     hues are not changed. Other commands stretch each of the color channels
  73.     separately, which changes the hues.
  74.   </p>
  75.       <p>
  76.     The way the stretching is done varies with the different commands and the
  77.     results look different. It is not easy to predict exactly what each
  78.     command will do. If you know exactly what you are doing, you can get the
  79.     same results, and even more, with the
  80.     <a class="link" href="gimp-tool-levels.html" title="5.6.¬† Levels">Levels</a> tool.
  81.   </p>
  82.       <p>
  83.     Here are examples of the results of these commands, all together on one
  84.     page, so you can compare them more easily. The most appropriate command
  85.     depends upon your image, so you should try each of them to see which
  86.     command works best on it.
  87.   </p>
  88.       <p>
  89.     </p>
  90.       <div class="figure">
  91.         <a id="id2707379"></a>
  92.         <p class="title">
  93.           <b>Figure¬†15.104.¬†
  94.         <span lang="en" xml:lang="en">
  95.           The original layer and its histograms
  96.         </span>
  97.       </b>
  98.         </p>
  99.         <div class="figure-contents">
  100.           <div class="mediaobject">
  101.             <img src="../images/menus/alice.png" alt="The original layer and its histograms" />
  102.             <div class="caption">
  103.               <p>
  104.             This layer doesn't have any very bright or very dark pixels, so
  105.             it works well with these commands.
  106.           </p>
  107.             </div>
  108.           </div>
  109.         </div>
  110.       </div>
  111.       <p><br class="figure-break" />
  112.   </p>
  113.       <p>
  114.     </p>
  115.       <div class="figure">
  116.         <a id="id2707420"></a>
  117.         <p class="title">
  118.           <b>Figure¬†15.105.¬†
  119.         <span lang="en" xml:lang="en">
  120.           The ‚Äú<span class="quote">Equalize</span>‚Äù command
  121.         </span>
  122.       </b>
  123.         </p>
  124.         <div class="figure-contents">
  125.           <div class="mediaobject">
  126.             <img src="../images/menus/equalize.png" alt="The Equalize command" />
  127.             <div class="caption">
  128.               <p>
  129.             <a class="link" href="gimp-layer-equalize.html" title="11.7.¬† Equalize">Equalize</a>
  130.           </p>
  131.             </div>
  132.           </div>
  133.         </div>
  134.       </div>
  135.       <p><br class="figure-break" />
  136.   </p>
  137.       <p>
  138.     </p>
  139.       <div class="figure">
  140.         <a id="id2707471"></a>
  141.         <p class="title">
  142.           <b>Figure¬†15.106.¬†
  143.         <span lang="en" xml:lang="en">
  144.           The ‚Äú<span class="quote">White Balance</span>‚Äù command
  145.         </span>
  146.       </b>
  147.         </p>
  148.         <div class="figure-contents">
  149.           <div class="mediaobject">
  150.             <img src="../images/menus/white-balance.png" alt="The White Balance command" />
  151.             <div class="caption">
  152.               <p>
  153.             <a class="link" href="gimp-layer-white-balance.html" title="11.8.¬† White Balance">White Balance</a>
  154.           </p>
  155.             </div>
  156.           </div>
  157.         </div>
  158.       </div>
  159.       <p><br class="figure-break" />
  160.   </p>
  161.       <p>
  162.     </p>
  163.       <div class="figure">
  164.         <a id="id2707523"></a>
  165.         <p class="title">
  166.           <b>Figure¬†15.107.¬†
  167.         <span lang="en" xml:lang="en">
  168.           The ‚Äú<span class="quote">Color Enhance</span>‚Äù command
  169.         </span>
  170.       </b>
  171.         </p>
  172.         <div class="figure-contents">
  173.           <div class="mediaobject">
  174.             <img src="../images/menus/color-enhance.png" alt="The Color Enhance command" />
  175.             <div class="caption">
  176.               <p>
  177.             <a class="link" href="plug-in-color-enhance.html" title="11.9.¬† Color Enhance">Color Enhance</a>
  178.           </p>
  179.             </div>
  180.           </div>
  181.         </div>
  182.       </div>
  183.       <p><br class="figure-break" />
  184.   </p>
  185.       <p>
  186.     </p>
  187.       <div class="figure">
  188.         <a id="id2707574"></a>
  189.         <p class="title">
  190.           <b>Figure¬†15.108.¬†
  191.         <span lang="en" xml:lang="en">
  192.           The ‚Äú<span class="quote">Normalize</span>‚Äù command
  193.         </span>
  194.       </b>
  195.         </p>
  196.         <div class="figure-contents">
  197.           <div class="mediaobject">
  198.             <img src="../images/menus/normalize.png" alt="The Normalize command" />
  199.             <div class="caption">
  200.               <p>
  201.             <a class="link" href="plug-in-normalize.html" title="11.10.¬† Normalize">Normalize</a>
  202.           </p>
  203.             </div>
  204.           </div>
  205.         </div>
  206.       </div>
  207.       <p><br class="figure-break" />
  208.   </p>
  209.       <p>
  210.     </p>
  211.       <div class="figure">
  212.         <a id="id2707625"></a>
  213.         <p class="title">
  214.           <b>Figure¬†15.109.¬†
  215.         <span lang="en" xml:lang="en">
  216.           The ‚Äú<span class="quote">Stretch Contrast</span>‚Äù command
  217.         </span>
  218.       </b>
  219.         </p>
  220.         <div class="figure-contents">
  221.           <div class="mediaobject">
  222.             <img src="../images/menus/c-stretch.png" alt="The Stretch Contrast command" />
  223.             <div class="caption">
  224.               <p>
  225.             <a class="link" href="plug-in-c-astretch.html" title="11.11.¬† Stretch Contrast">Stretch Contrast</a>
  226.           </p>
  227.             </div>
  228.           </div>
  229.         </div>
  230.       </div>
  231.       <p><br class="figure-break" />
  232.   </p>
  233.       <p>
  234.     </p>
  235.       <div class="figure">
  236.         <a id="id2707676"></a>
  237.         <p class="title">
  238.           <b>Figure¬†15.110.¬†
  239.         <span lang="en" xml:lang="en">
  240.           The ‚Äú<span class="quote">Stretch HSV</span>‚Äù command
  241.         </span>
  242.       </b>
  243.         </p>
  244.         <div class="figure-contents">
  245.           <div class="mediaobject">
  246.             <img src="../images/menus/stretch-hsv.png" alt="The Stretch HSV command" />
  247.             <div class="caption">
  248.               <p>
  249.             <a class="link" href="plug-in-autostretch-hsv.html" title="11.12.¬† Stretch HSV">Stretch HSV</a>
  250.           </p>
  251.             </div>
  252.           </div>
  253.         </div>
  254.       </div>
  255.       <p><br class="figure-break" />
  256.   </p>
  257.     </div>
  258.     <div class="navfooter">
  259.       <hr />
  260.       <table width="100%" summary="Navigation footer">
  261.         <tr>
  262.           <td width="40%" align="left"><a accesskey="p" href="gimp-layer-reverse.html"><img src="../images/prev.png" alt="Prev" /></a>¬†</td>
  263.           <td width="20%" align="center">
  264.             <a accesskey="u" href="gimp-layer-menu.html">
  265.               <img src="../images/up.png" alt="Up" />
  266.             </a>
  267.           </td>
  268.           <td width="40%" align="right">¬†<a accesskey="n" href="plug-in-autocrop.html"><img src="../images/next.png" alt="Next" /></a></td>
  269.         </tr>
  270.         <tr>
  271.           <td width="40%" align="left" valign="top"><a accesskey="p" href="gimp-layer-reverse.html">10.17.¬†
  272.     <span lang="en" xml:lang="en">The ‚Äú<span class="quote">Reverse Layer Order</span>‚Äù command</span>
  273.   </a>¬†</td>
  274.           <td width="20%" align="center">
  275.             <a accesskey="h" href="index.html">
  276.               <img src="../images/home.png" alt="Home" />
  277.             </a>
  278.           </td>
  279.           <td width="40%" align="right" valign="top">¬†<a accesskey="n" href="plug-in-autocrop.html">10.19.¬†
  280.     <span lang="en" xml:lang="en">Autocrop Layer</span>
  281.   </a></td>
  282.         </tr>
  283.       </table>
  284.     </div>
  285.   </body>
  286. </html>
  287.