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  6.     <title>8.7.¬† Lens Distortion</title>
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  14.     <link rel="prev" href="plug-in-mosaic.html" title="8.6.¬† Mosaic" />
  15.     <link rel="next" href="plug-in-polar-coords.html" title="8.8.¬† Polar Coords" />
  16.   </head>
  17.   <body>
  18.     <div class="navheader">
  19.       <table width="100%" summary="Navigation header">
  20.         <tr>
  21.           <th colspan="3" align="center">8.7.¬†
  22.     <span lang="en" xml:lang="en">Lens Distortion</span>
  23.   </th>
  24.         </tr>
  25.         <tr>
  26.           <td width="20%" align="left"><a accesskey="p" href="plug-in-mosaic.html"><img src="../images/prev.png" alt="Prev" /></a>¬†</td>
  27.           <th width="60%" align="center">8.¬†
  28.     <span lang="en" xml:lang="en">Distort Filters</span>
  29.   </th>
  30.           <td width="20%" align="right">¬†<a accesskey="n" href="plug-in-polar-coords.html"><img src="../images/next.png" alt="Next" /></a></td>
  31.         </tr>
  32.       </table>
  33.       <hr />
  34.     </div>
  35.     <div class="sect2" lang="en" xml:lang="en">
  36.       <div class="titlepage">
  37.         <div>
  38.           <div>
  39.             <h3 class="title"><a id="plug-in-lens-distortion"></a>8.7.¬†
  40.     <span lang="en" xml:lang="en">Lens Distortion</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: 2440 $</td>
  53.                   <td align="left">2008-01-03</td>
  54.                   <td align="left">alex falappa</td>
  55.                 </tr>
  56.               </table>
  57.             </div>
  58.           </div>
  59.         </div>
  60.       </div>
  61.       <a id="id2750473" class="indexterm"></a>
  62.       <a id="id2750491" class="indexterm"></a>
  63.       <div class="sect3" lang="en" xml:lang="en">
  64.         <div class="titlepage">
  65.           <div>
  66.             <div>
  67.               <h4 class="title"><a id="id2750500"></a>8.7.1.¬†
  68.       <span lang="en" xml:lang="en">Overview</span>
  69.     </h4>
  70.             </div>
  71.           </div>
  72.         </div>
  73.         <div class="figure">
  74.           <a id="id2750510"></a>
  75.           <p class="title">
  76.             <b>Figure¬†16.114.¬†
  77.         <span lang="en" xml:lang="en">
  78.           Example for the ‚Äú<span class="quote">Lens Distortion</span>‚Äù filter
  79.         </span>
  80.       </b>
  81.           </p>
  82.           <div class="figure-contents">
  83.             <div class="mediaobject">
  84.               <img src="../images/filters/examples/taj_orig.jpg" alt="Example for the Lens Distortion filter" />
  85.               <div class="caption">
  86.                 <p>Original image</p>
  87.               </div>
  88.             </div>
  89.             <div class="mediaobject">
  90.               <img src="../images/filters/examples/distort-taj-lens-distortion.jpg" alt="Example for the Lens Distortion filter" />
  91.               <div class="caption">
  92.                 <p>‚Äú<span class="quote">Lens Distortion</span>‚Äù applied</p>
  93.               </div>
  94.             </div>
  95.           </div>
  96.         </div>
  97.         <br class="figure-break" />
  98.         <p>
  99.       This filter lets you simulate but also correct the typical distortion
  100.       effect introduced in photo images by the glasses contained in the camera
  101.       lenses.
  102.     </p>
  103.         <p>
  104.       The allowed range of all options is from -100.0 to 100.0.
  105.     </p>
  106.       </div>
  107.       <div class="sect3" lang="en" xml:lang="en">
  108.         <div class="titlepage">
  109.           <div>
  110.             <div>
  111.               <h4 class="title"><a id="id2750591"></a>8.7.2.¬†
  112.       <span lang="en" xml:lang="en">Activate the filter</span>
  113.     </h4>
  114.             </div>
  115.           </div>
  116.         </div>
  117.         <p>
  118.       This filter is found in the image window menu under
  119.       <span class="guimenu"><span class="accel">F</span>ilters</span> ‚Üí <span class="guisubmenu">Distorts</span> ‚Üí <span class="guimenuitem">Lens Distortion</span>.
  120.     </p>
  121.       </div>
  122.       <div class="sect3" lang="en" xml:lang="en">
  123.         <div class="titlepage">
  124.           <div>
  125.             <div>
  126.               <h4 class="title"><a id="id2750637"></a>8.7.3.¬†
  127.       <span lang="en" xml:lang="en">Options</span>
  128.     </h4>
  129.             </div>
  130.           </div>
  131.         </div>
  132.         <div class="figure">
  133.           <a id="id2750648"></a>
  134.           <p class="title">
  135.             <b>Figure¬†16.115.¬†
  136.         <span lang="en" xml:lang="en">‚Äú<span class="quote">Lens Distortion</span>‚Äù options</span>
  137.       </b>
  138.           </p>
  139.           <div class="figure-contents">
  140.             <div class="mediaobject">
  141.               <img src="../images/filters/options-distort-lens-distortion.png" alt="Lens Distortion options" />
  142.             </div>
  143.           </div>
  144.         </div>
  145.         <br class="figure-break" />
  146.         <div class="variablelist">
  147.           <dl>
  148.             <dt>
  149.               <span class="term">Preview</span>
  150.             </dt>
  151.             <dd>
  152.               <p>
  153.             The result of your settings will appear in the Preview without
  154.             affecting the image until you click on <span class="guibutton">OK</span>.
  155.           </p>
  156.             </dd>
  157.             <dt>
  158.               <span class="term">Main</span>
  159.             </dt>
  160.             <dd>
  161.               <p>
  162.             The amount of spherical correction to introduce. Positive values
  163.             make the image convex while negative ones make it concave. The
  164.             whole effect is similar to wrapping the image inside or outside a
  165.             sphere.
  166.           </p>
  167.               <div class="figure">
  168.                 <a id="id2750727"></a>
  169.                 <p class="title">
  170.                   <b>Figure¬†16.116.¬†
  171.               <span lang="en" xml:lang="en">
  172.                 Example result of Main option
  173.               </span>
  174.             </b>
  175.                 </p>
  176.                 <div class="figure-contents">
  177.                   <div class="mediaobject">
  178.                     <img src="../images/filters/examples/lensdistortion-main-low.png" alt="Example result of Main option" />
  179.                     <div class="caption">
  180.                       <p>-100.0</p>
  181.                     </div>
  182.                   </div>
  183.                   <div class="mediaobject">
  184.                     <img src="../images/filters/examples/lensdistortion-original.png" alt="Example result of Main option" />
  185.                     <div class="caption">
  186.                       <p>0.0</p>
  187.                     </div>
  188.                   </div>
  189.                   <div class="mediaobject">
  190.                     <img src="../images/filters/examples/lensdistortion-main-high.png" alt="Example result of Main option" />
  191.                     <div class="caption">
  192.                       <p>+100.0</p>
  193.                     </div>
  194.                   </div>
  195.                 </div>
  196.               </div>
  197.               <br class="figure-break" />
  198.             </dd>
  199.             <dt>
  200.               <span class="term">Edge</span>
  201.             </dt>
  202.             <dd>
  203.               <p>
  204.             Specifies the amount of additional spherical correction at image
  205.             edges.
  206.           </p>
  207.               <div class="figure">
  208.                 <a id="id2750814"></a>
  209.                 <p class="title">
  210.                   <b>Figure¬†16.117.¬†
  211.               <span lang="en" xml:lang="en">
  212.                 Example result of Edge option (Main set to 50.0)
  213.               </span>
  214.             </b>
  215.                 </p>
  216.                 <div class="figure-contents">
  217.                   <div class="mediaobject">
  218.                     <img src="../images/filters/examples/lensdistortion-edge-low.png" alt="Example result of Edge option (Main set to 50.0)" />
  219.                     <div class="caption">
  220.                       <p>-60.0</p>
  221.                     </div>
  222.                   </div>
  223.                   <div class="mediaobject">
  224.                     <img src="../images/filters/examples/lensdistortion-original.png" alt="Example result of Edge option (Main set to 50.0)" />
  225.                     <div class="caption">
  226.                       <p>0.0</p>
  227.                     </div>
  228.                   </div>
  229.                   <div class="mediaobject">
  230.                     <img src="../images/filters/examples/lensdistortion-edge-high.png" alt="Example result of Edge option (Main set to 50.0)" />
  231.                     <div class="caption">
  232.                       <p>+60.0</p>
  233.                     </div>
  234.                   </div>
  235.                 </div>
  236.               </div>
  237.               <br class="figure-break" />
  238.             </dd>
  239.             <dt>
  240.               <span class="term">Zoom</span>
  241.             </dt>
  242.             <dd>
  243.               <p>
  244.             Specifies the amount of the image enlargement or reduction caused by
  245.             the hypotethical lens.
  246.           </p>
  247.               <div class="figure">
  248.                 <a id="id2750903"></a>
  249.                 <p class="title">
  250.                   <b>Figure¬†16.118.¬†
  251.               <span lang="en" xml:lang="en">
  252.                 Example result of Zoom option
  253.               </span>
  254.             </b>
  255.                 </p>
  256.                 <div class="figure-contents">
  257.                   <div class="mediaobject">
  258.                     <img src="../images/filters/examples/lensdistortion-zoom-low.png" alt="Example result of Zoom option" />
  259.                     <div class="caption">
  260.                       <p>-100.0</p>
  261.                     </div>
  262.                   </div>
  263.                   <div class="mediaobject">
  264.                     <img src="../images/filters/examples/lensdistortion-original.png" alt="Example result of Zoom option" />
  265.                     <div class="caption">
  266.                       <p>0.0</p>
  267.                     </div>
  268.                   </div>
  269.                   <div class="mediaobject">
  270.                     <img src="../images/filters/examples/lensdistortion-zoom-high.png" alt="Example result of Zoom option" />
  271.                     <div class="caption">
  272.                       <p>+100.0</p>
  273.                     </div>
  274.                   </div>
  275.                 </div>
  276.               </div>
  277.               <br class="figure-break" />
  278.             </dd>
  279.             <dt>
  280.               <span class="term">Brighten</span>
  281.             </dt>
  282.             <dd>
  283.               <p>
  284.             The amount of the ‚Äú<span class="quote">vignetting</span>‚Äù effect: the brightness
  285.             decrease/increase due to the lens curvature that produces a
  286.             different light absorption.            
  287.           </p>
  288.               <p>
  289.             The <span class="guilabel">Main</span> or <span class="guilabel">Edge</span> options
  290.             must be non zero for this option to produce noticeable results.
  291.           </p>
  292.               <div class="figure">
  293.                 <a id="id2751015"></a>
  294.                 <p class="title">
  295.                   <b>Figure¬†16.119.¬†
  296.               <span lang="en" xml:lang="en">
  297.                 Example result of Brigthen option (Main set to 75.0)
  298.               </span>
  299.             </b>
  300.                 </p>
  301.                 <div class="figure-contents">
  302.                   <div class="mediaobject">
  303.                     <img src="../images/filters/examples/lensdistortion-brighten-low.png" alt="Example result of Brigthen option (Main set to 75.0)" />
  304.                     <div class="caption">
  305.                       <p>-25.0</p>
  306.                     </div>
  307.                   </div>
  308.                   <div class="mediaobject">
  309.                     <img src="../images/filters/examples/lensdistortion-original.png" alt="Example result of Brigthen option (Main set to 75.0)" />
  310.                     <div class="caption">
  311.                       <p>0.0</p>
  312.                     </div>
  313.                   </div>
  314.                   <div class="mediaobject">
  315.                     <img src="../images/filters/examples/lensdistortion-brighten-high.png" alt="Example result of Brigthen option (Main set to 75.0)" />
  316.                     <div class="caption">
  317.                       <p>+25.0</p>
  318.                     </div>
  319.                   </div>
  320.                 </div>
  321.               </div>
  322.               <br class="figure-break" />
  323.             </dd>
  324.             <dt>
  325.               <span class="term">X shift; Y shift</span>
  326.             </dt>
  327.             <dd>
  328.               <p>
  329.             These two options specify the shift of the image produced by not
  330.             perfectly centered pairs of lenses.
  331.           </p>
  332.               <p>
  333.             As above this option produces visible results only if the
  334.             <span class="guilabel">Main</span> or <span class="guilabel">Edge</span> options
  335.             are non zero.
  336.           </p>
  337.               <div class="figure">
  338.                 <a id="id2751123"></a>
  339.                 <p class="title">
  340.                   <b>Figure¬†16.120.¬†
  341.               <span lang="en" xml:lang="en">
  342.                 Example result of X shift option (Main set to 70.0)
  343.               </span>
  344.             </b>
  345.                 </p>
  346.                 <div class="figure-contents">
  347.                   <div class="mediaobject">
  348.                     <img src="../images/filters/examples/lensdistortion-xshift-low.png" alt="Example result of X shift option (Main set to 70.0)" />
  349.                     <div class="caption">
  350.                       <p>-100.0</p>
  351.                     </div>
  352.                   </div>
  353.                   <div class="mediaobject">
  354.                     <img src="../images/filters/examples/lensdistortion-original.png" alt="Example result of X shift option (Main set to 70.0)" />
  355.                     <div class="caption">
  356.                       <p>0.0</p>
  357.                     </div>
  358.                   </div>
  359.                   <div class="mediaobject">
  360.                     <img src="../images/filters/examples/lensdistortion-xshift-high.png" alt="Example result of X shift option (Main set to 70.0)" />
  361.                     <div class="caption">
  362.                       <p>+100.0</p>
  363.                     </div>
  364.                   </div>
  365.                 </div>
  366.               </div>
  367.               <br class="figure-break" />
  368.             </dd>
  369.           </dl>
  370.         </div>
  371.       </div>
  372.     </div>
  373.     <div class="navfooter">
  374.       <hr />
  375.       <table width="100%" summary="Navigation footer">
  376.         <tr>
  377.           <td width="40%" align="left"><a accesskey="p" href="plug-in-mosaic.html"><img src="../images/prev.png" alt="Prev" /></a>¬†</td>
  378.           <td width="20%" align="center">
  379.             <a accesskey="u" href="filters-distort.html">
  380.               <img src="../images/up.png" alt="Up" />
  381.             </a>
  382.           </td>
  383.           <td width="40%" align="right">¬†<a accesskey="n" href="plug-in-polar-coords.html"><img src="../images/next.png" alt="Next" /></a></td>
  384.         </tr>
  385.         <tr>
  386.           <td width="40%" align="left" valign="top"><a accesskey="p" href="plug-in-mosaic.html">8.6.¬†
  387.     <span lang="en" xml:lang="en">Mosaic</span>
  388.   </a>¬†</td>
  389.           <td width="20%" align="center">
  390.             <a accesskey="h" href="index.html">
  391.               <img src="../images/home.png" alt="Home" />
  392.             </a>
  393.           </td>
  394.           <td width="40%" align="right" valign="top">¬†<a accesskey="n" href="plug-in-polar-coords.html">8.8.¬†
  395.     <span lang="en" xml:lang="en">Polar Coords</span>
  396.   </a></td>
  397.         </tr>
  398.       </table>
  399.     </div>
  400.   </body>
  401. </html>
  402.