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  6.     <title>3.7.¬† Eraser</title>
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  13.     <link rel="up" href="gimp-tools-paint.html" title="3.¬† Brush Tools" />
  14.     <link rel="prev" href="gimp-tool-paintbrush.html" title="3.6.¬† Paintbrush" />
  15.     <link rel="next" href="gimp-tool-airbrush.html" title="3.8.¬† Airbrush Tool" />
  16.   </head>
  17.   <body>
  18.     <div class="navheader">
  19.       <table width="100%" summary="Navigation header">
  20.         <tr>
  21.           <th colspan="3" align="center">3.7.¬†
  22.     <span lang="en" xml:lang="en">Eraser</span>
  23.   </th>
  24.         </tr>
  25.         <tr>
  26.           <td width="20%" align="left"><a accesskey="p" href="gimp-tool-paintbrush.html"><img src="../images/prev.png" alt="Prev" /></a>¬†</td>
  27.           <th width="60%" align="center">3.¬†
  28.     <span lang="en" xml:lang="en">Brush Tools</span>
  29.   </th>
  30.           <td width="20%" align="right">¬†<a accesskey="n" href="gimp-tool-airbrush.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="gimp-tool-eraser"></a>3.7.¬†
  40.     <span lang="en" xml:lang="en">Eraser</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: 2429 $</td>
  53.                   <td align="left">2006-06-04</td>
  54.                   <td align="left">j.h</td>
  55.                 </tr>
  56.               </table>
  57.             </div>
  58.           </div>
  59.         </div>
  60.       </div>
  61.       <a id="id2632070" class="indexterm"></a>
  62.       <a id="id2632083" class="indexterm"></a>
  63.       <a id="id2632092" class="indexterm"></a>
  64.       <div class="figure">
  65.         <a id="id2632105"></a>
  66.         <p class="title">
  67.           <b>Figure¬†13.59.¬†
  68.       <span lang="en" xml:lang="en">Eraser tool icon in the Toolbox</span>
  69.     </b>
  70.         </p>
  71.         <div class="figure-contents">
  72.           <div class="mediaobject">
  73.             <img src="../images/toolbox/toolbox-eraser.png" alt="Eraser tool icon in the Toolbox" />
  74.           </div>
  75.         </div>
  76.       </div>
  77.       <br class="figure-break" />
  78.       <p>
  79.     The Eraser is used to remove areas of color from the current layer or from
  80.     a selection of this layer. If the Eraser is used on something that does
  81.     not support transparency (a selection mask channel, a layer mask, or the
  82.     Background layer if it lacks an alpha channel), then erasing will show the
  83.     background color, as displayed in the Color Area of the Toolbox (in case
  84.     of a mask, the selection will be modified). Otherwise, erasing will
  85.     produce either partial or full transparency, depending on the settings for
  86.     the tool options. You can learn more on how to add an alpha channel to a
  87.     layer in <a class="xref" href="gimp-layer-alpha-add.html" title="10.32.¬† Add Alpha Channel">Section¬†10.32, ‚Äú
  88.     <span lang="en" xml:lang="en">Add Alpha Channel</span>
  89.   ‚Äù</a>.
  90.   </p>
  91.       <p>
  92.     If you need to erase some group of pixels completely, leaving no trace
  93.     behind of their previous contents, you should check the "Hard edge" box in
  94.     the Tool Options. Otherwise, sub-pixel brush placement will cause partial
  95.     erasure at the edges of the brush-stroke, even if you use a hard-edged
  96.     brush.
  97.   </p>
  98.       <div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;">
  99.         <table border="0" summary="Tip">
  100.           <tr>
  101.             <td rowspan="2" align="center" valign="top" width="25">
  102.               <img alt="[Tip]" src="../images/tip.png" />
  103.             </td>
  104.             <th align="left">Tip</th>
  105.           </tr>
  106.           <tr>
  107.             <td align="left" valign="top">
  108.               <p>
  109.       If you use GIMP with a tablet, you may find it convenient to treat the
  110.       reverse end of the stylus as an eraser. To make this work, all you need
  111.       to do is click the reverse end on the Eraser tool in the Toolbox.
  112.       Because each end of the stylus is treated as a separate input device,
  113.       and each input device has its own separate tool assignment, the reverse
  114.       end will then continue to function as an Eraser as long as you don't
  115.       select a different tool with it.
  116.     </p>
  117.             </td>
  118.           </tr>
  119.         </table>
  120.       </div>
  121.       <div class="sect3" lang="en" xml:lang="en">
  122.         <div class="titlepage">
  123.           <div>
  124.             <div>
  125.               <h4 class="title"><a id="id2632198"></a>3.7.1.¬†
  126.       <span lang="en" xml:lang="en">How to Activate</span>
  127.     </h4>
  128.             </div>
  129.           </div>
  130.         </div>
  131.         <p>You can activate the Eraser tool in several ways :</p>
  132.         <div class="itemizedlist">
  133.           <ul type="disc">
  134.             <li>
  135.               <p>
  136.           From the image menu through
  137.           <span class="guimenu">Tools</span> ‚Üí <span class="guisubmenu">Paint Tools</span> ‚Üí <span class="guimenuitem">Eraser</span>;
  138.         </p>
  139.             </li>
  140.             <li>
  141.               <p>
  142.           from the Toolbox by clicking on the tool icon
  143.           <span class="guiicon">
  144.             <span class="inlinemediaobject"><img src="../images/toolbox/stock-tool-eraser-22.png" /></span>
  145.           </span>;
  146.         </p>
  147.             </li>
  148.             <li>
  149.               <p>
  150.           or from the keyboard using the shortcut
  151.           <span class="keycap"><strong>Shift</strong></span>+<span class="keycap"><strong>E</strong></span>.
  152.         </p>
  153.             </li>
  154.           </ul>
  155.         </div>
  156.       </div>
  157.       <div class="sect3" lang="en" xml:lang="en">
  158.         <div class="titlepage">
  159.           <div>
  160.             <div>
  161.               <h4 class="title"><a id="id2632303"></a>3.7.2.¬†
  162.       <span lang="en" xml:lang="en">Key modifiers</span>
  163.     </h4>
  164.             </div>
  165.           </div>
  166.         </div>
  167.         <p>
  168.       See the <a class="xref" href="gimp-tools-paint.html#gimp-tool-brush" title="3.1.¬† Common Features">Section¬†3.1, ‚Äú
  169.     <span lang="en" xml:lang="en">Common Features</span>
  170.   ‚Äù</a> for a description of key
  171.       modifiers that have the same effect on all brush tools.
  172.     </p>
  173.         <div class="variablelist">
  174.           <dl>
  175.             <dt>
  176.               <span class="term">
  177.                 <span class="keycap">
  178.                   <strong>Ctrl</strong>
  179.                 </span>
  180.               </span>
  181.             </dt>
  182.             <dd>
  183.               <p>
  184.             For the Eraser, holding down the <span class="keycap"><strong>Ctrl</strong></span> key puts it
  185.             into ‚Äú<span class="quote">color picker</span>‚Äù mode, so that it selects the
  186.             color of any pixel it is clicked on. Unlike other brush tools,
  187.             however, the Eraser sets the <span class="emphasis"><em>background</em></span>
  188.             color rather than the foreground color. This is more useful,
  189.             because on drawables that don't support transparency, erasing
  190.             replaces the erased areas with the current background color.
  191.           </p>
  192.             </dd>
  193.             <dt>
  194.               <span class="term">
  195.                 <span class="keycap">
  196.                   <strong>Alt</strong>
  197.                 </span>
  198.               </span>
  199.             </dt>
  200.             <dd>
  201.               <p>
  202.             For the Eraser, holding down the <span class="keycap"><strong>Alt</strong></span> key switches
  203.             it into ‚Äú<span class="quote">anti-erase</span>‚Äù mode, as described below in the
  204.             Tool Options section. Note that on some systems, the
  205.             <span class="keycap"><strong>Alt</strong></span> key is trapped by the Window Manager. If this
  206.             happens to you, you may be able to use
  207.             <span class="keycap"><strong>Alt</strong></span>+<span class="keycap"><strong>Shift</strong></span>
  208.             instead.
  209.           </p>
  210.             </dd>
  211.           </dl>
  212.         </div>
  213.       </div>
  214.       <div class="sect3" lang="en" xml:lang="en">
  215.         <div class="titlepage">
  216.           <div>
  217.             <div>
  218.               <h4 class="title"><a id="id2632425"></a>3.7.3.¬†
  219.       <span lang="en" xml:lang="en">Tool Options</span>
  220.     </h4>
  221.             </div>
  222.           </div>
  223.         </div>
  224.         <div class="figure">
  225.           <a id="id2632436"></a>
  226.           <p class="title">
  227.             <b>Figure¬†13.60.¬†
  228.         <span lang="en" xml:lang="en">Tool Options for the Eraser tool</span>
  229.       </b>
  230.           </p>
  231.           <div class="figure-contents">
  232.             <div class="mediaobject">
  233.               <img src="../images/toolbox/tool-options-eraser.png" alt="Tool Options for the Eraser tool" />
  234.             </div>
  235.           </div>
  236.         </div>
  237.         <br class="figure-break" />
  238.         <div class="variablelist">
  239.           <dl>
  240.             <dt>
  241.               <span class="term">
  242.           Brush; Pressure sensitivity; Scale; Fade out; Incremental;
  243.           Hard edges
  244.         </span>
  245.             </dt>
  246.             <dd>
  247.               <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
  248.                 <table border="0" summary="Note">
  249.                   <tr>
  250.                     <td rowspan="2" align="center" valign="top" width="25">
  251.                       <img alt="[Note]" src="../images/note.png" />
  252.                     </td>
  253.                     <th align="left">Note</th>
  254.                   </tr>
  255.                   <tr>
  256.                     <td align="left" valign="top">
  257.                       <p>
  258.     See the <a class="link" href="gimp-tools-paint.html#gimp-tool-brush-options" title="3.1.2.¬† Tool Options">Brush Tools Overview</a> for a
  259.     description of tool options that apply to many or all brush tools.
  260.   </p>
  261.                     </td>
  262.                   </tr>
  263.                 </table>
  264.               </div>
  265.             </dd>
  266.             <dt>
  267.               <span class="term">Opacity</span>
  268.             </dt>
  269.             <dd>
  270.               <p>
  271.             The <span class="guilabel">Opacity</span> slider, in spite of its name,
  272.             determines the ‚Äú<span class="quote">strength</span>‚Äù of the tool. Thus, when
  273.             you erase on a layer with an alpha channel, the higher the
  274.             opacity you use, the more transparency you get!
  275.           </p>
  276.             </dd>
  277.             <dt>
  278.               <span class="term">Anti Erase</span>
  279.             </dt>
  280.             <dd>
  281.               <p>
  282.             The Anti Erase option of the Erase tool can un-erase areas of an
  283.             image, even if they are completely transparent. This feature only
  284.             works when used on layers with an alpha channel. In addition to
  285.             the check-button in the Tool Options, it can also be activated
  286.             on-the-fly by holding down the <span class="keycap"><strong>Alt</strong></span> key (or, if
  287.             the <span class="keycap"><strong>Alt</strong></span> key is trapped by the Window Manager, by
  288.             holding down
  289.             <span class="keycap"><strong>Alt</strong></span>+<span class="keycap"><strong>Shift</strong></span>).
  290.           </p>
  291.               <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
  292.                 <table border="0" summary="Note">
  293.                   <tr>
  294.                     <td rowspan="2" align="center" valign="top" width="25">
  295.                       <img alt="[Note]" src="../images/note.png" />
  296.                     </td>
  297.                     <th align="left">Note</th>
  298.                   </tr>
  299.                   <tr>
  300.                     <td align="left" valign="top">
  301.                       <p>
  302.               To understand how anti-erasing is possible, you should realize
  303.               that erasing (or cutting, for that matter) only affects the
  304.               alpha channel, not the RGB channels that contain the image data.
  305.               Even if the result is completely transparent, the RGB data is
  306.               still there, you simply can't see it. Anti-erasing increases the
  307.               alpha value so that you can see the RGB data once again.
  308.             </p>
  309.                       <p>
  310.               An annoying feature: on a layer you have created with a
  311.               transparent background, using anti-erasing on non-painted areas
  312.               paints with black!
  313.             </p>
  314.                     </td>
  315.                   </tr>
  316.                 </table>
  317.               </div>
  318.             </dd>
  319.           </dl>
  320.         </div>
  321.         <div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;">
  322.           <table border="0" summary="Tip">
  323.             <tr>
  324.               <td rowspan="2" align="center" valign="top" width="25">
  325.                 <img alt="[Tip]" src="../images/tip.png" />
  326.               </td>
  327.               <th align="left"><a id="change-selection-shape"></a>Tip</th>
  328.             </tr>
  329.             <tr>
  330.               <td align="left" valign="top">
  331.                 <a id="id2632620" class="indexterm"></a>
  332.                 <p>
  333.         You can use the Eraser tool to change the shape of a floating
  334.         selection. By erasing, you trim the edges of the selection. By
  335.         inverting the selection before floating it, erasing will increase the
  336.         size of a part of the selection.
  337.       </p>
  338.               </td>
  339.             </tr>
  340.           </table>
  341.         </div>
  342.       </div>
  343.     </div>
  344.     <div class="navfooter">
  345.       <hr />
  346.       <table width="100%" summary="Navigation footer">
  347.         <tr>
  348.           <td width="40%" align="left"><a accesskey="p" href="gimp-tool-paintbrush.html"><img src="../images/prev.png" alt="Prev" /></a>¬†</td>
  349.           <td width="20%" align="center">
  350.             <a accesskey="u" href="gimp-tools-paint.html">
  351.               <img src="../images/up.png" alt="Up" />
  352.             </a>
  353.           </td>
  354.           <td width="40%" align="right">¬†<a accesskey="n" href="gimp-tool-airbrush.html"><img src="../images/next.png" alt="Next" /></a></td>
  355.         </tr>
  356.         <tr>
  357.           <td width="40%" align="left" valign="top"><a accesskey="p" href="gimp-tool-paintbrush.html">3.6.¬†
  358.     <span lang="en" xml:lang="en">Paintbrush</span>
  359.   </a>¬†</td>
  360.           <td width="20%" align="center">
  361.             <a accesskey="h" href="index.html">
  362.               <img src="../images/home.png" alt="Home" />
  363.             </a>
  364.           </td>
  365.           <td width="40%" align="right" valign="top">¬†<a accesskey="n" href="gimp-tool-airbrush.html">3.8.¬†
  366.     <span lang="en" xml:lang="en">Airbrush Tool</span>
  367.   </a></td>
  368.         </tr>
  369.       </table>
  370.     </div>
  371.   </body>
  372. </html>
  373.