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<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"/><title>6 Bilder konstruieren: "image.ss"</title><link rel="stylesheet" type="text/css" href="../scribble.css" title="default"/><link rel="stylesheet" type="text/css" href="../racket.css" title="default"/><link rel="stylesheet" type="text/css" href="../manual-style.css" title="default"/><link rel="stylesheet" type="text/css" href="../manual-racket.css" title="default"/><link rel="stylesheet" type="text/css" href="../doc-site.css" title="default"/><script type="text/javascript" src="../scribble-common.js"></script><script type="text/javascript" src="../manual-racket.js"></script><script type="text/javascript" src="../doc-site.js"></script><script type="text/javascript" src="../local-redirect/local-redirect.js"></script><script type="text/javascript" src="../local-redirect/local-user-redirect.js"></script><!--[if IE 6]><style type="text/css">.SIEHidden { overflow: hidden; }</style><![endif]--></head><body id="doc-racket-lang-org"><div class="tocset"><div class="tocview"><div class="tocviewlist tocviewlisttopspace"><div class="tocviewtitle"><table cellspacing="0" cellpadding="0"><tr><td style="width: 1em;"><a href="javascript:void(0);" title="Expand/Collapse" class="tocviewtoggle" onclick="TocviewToggle(this,"tocview_0");">▼</a></td><td></td><td><a href="index.html" class="tocviewlink" data-pltdoc="x">Sprachebenen und Material zu <span style="font-style: italic">Die Macht der Abstraktion</span></a></td></tr></table></div><div class="tocviewsublisttop" style="display: block;" id="tocview_0"><table cellspacing="0" cellpadding="0"><tr><td align="right">1 </td><td><a href="DMdA-beginner.html" class="tocviewlink" data-pltdoc="x">Die Macht der Abstraktion -<wbr></wbr> Anfänger</a></td></tr><tr><td align="right">2 </td><td><a href="DMdA-vanilla.html" class="tocviewlink" data-pltdoc="x">Die Macht der Abstraktion</a></td></tr><tr><td align="right">3 </td><td><a href="DMdA-assignments.html" class="tocviewlink" data-pltdoc="x">Die Macht der Abstraktion mit Zuweisungen</a></td></tr><tr><td align="right">4 </td><td><a href="DMdA-advanced.html" class="tocviewlink" data-pltdoc="x">Die Macht der Abstraktion fortgeschritten</a></td></tr><tr><td align="right">5 </td><td><a href="Konstruktionsanleitungen_1_bis_10.html" class="tocviewlink" data-pltdoc="x">Konstruktionsanleitungen 1 bis 10</a></td></tr><tr><td align="right">6 </td><td><a href="" class="tocviewselflink" data-pltdoc="x">Bilder konstruieren:<span class="mywbr"> </span> <span class="stt">"image.ss"</span><a name="(idx._(gentag._2._(lib._deinprogramm/scribblings/deinprogramm..scrbl)))"></a></a></td></tr><tr><td align="right">7 </td><td><a href="world.html" class="tocviewlink" data-pltdoc="x">Animationen:<span class="mywbr"> </span> <span class="stt">"world.ss"</span><a name="(idx._(gentag._3._(lib._deinprogramm/scribblings/deinprogramm..scrbl)))"></a></a></td></tr><tr><td align="right">8 </td><td><a href="turtle.html" class="tocviewlink" data-pltdoc="x">Turtle-<wbr></wbr>Grafik:<span class="mywbr"> </span> <span class="stt">"turtle.ss"</span><a name="(idx._(gentag._4._(lib._deinprogramm/scribblings/deinprogramm..scrbl)))"></a></a></td></tr><tr><td align="right">9 </td><td><a href="sound.html" class="tocviewlink" data-pltdoc="x">Abspielen von Audio-<wbr></wbr>Dateien:<span class="mywbr"> </span> <span class="stt">"sound.ss"</span><a name="(idx._(gentag._5._(lib._deinprogramm/scribblings/deinprogramm..scrbl)))"></a></a></td></tr><tr><td align="right">10 </td><td><a href="line3d.html" class="tocviewlink" data-pltdoc="x">3D-<wbr></wbr>Liniengraphik:<span class="mywbr"> </span> <span class="stt">"line3d.ss"</span><a name="(idx._(gentag._6._(lib._deinprogramm/scribblings/deinprogramm..scrbl)))"></a></a></td></tr><tr><td align="right">11 </td><td><a href="DMdA__Sprachen_als_Libraries.html" class="tocviewlink" data-pltdoc="x"><span style="font-weight: bold">DMd<span class="mywbr"> </span>A</span>:<span class="mywbr"> </span> Sprachen als Libraries</a></td></tr><tr><td align="right"></td><td><a href="doc-index.html" class="tocviewlink" data-pltdoc="x">Index</a></td></tr></table></div></div><div class="tocviewlist"><table cellspacing="0" cellpadding="0"><tr><td style="width: 1em;"><a href="javascript:void(0);" title="Expand/Collapse" class="tocviewtoggle" onclick="TocviewToggle(this,"tocview_1");">►</a></td><td>6 </td><td><a href="" class="tocviewselflink" data-pltdoc="x">Bilder konstruieren:<span class="mywbr"> </span> <span class="stt">"image.ss"</span><a name="(idx._(gentag._2._(lib._deinprogramm/scribblings/deinprogramm..scrbl)))"></a></a></td></tr></table><div class="tocviewsublistbottom" style="display: none;" id="tocview_1"><table cellspacing="0" cellpadding="0"><tr><td align="right">6.1 </td><td><a href="#%28part._.Bilder%29" class="tocviewlink" data-pltdoc="x">Bilder</a></td></tr><tr><td align="right">6.2 </td><td><a href="#%28part._modes-colors%29" class="tocviewlink" data-pltdoc="x">Modi und Farben</a></td></tr><tr><td align="right">6.3 </td><td><a href="#%28part._creational%29" class="tocviewlink" data-pltdoc="x">Einfache geometrische Figuren</a></td></tr><tr><td align="right">6.4 </td><td><a href="#%28part._properties%29" class="tocviewlink" data-pltdoc="x">Eigenschaften von Bildern</a></td></tr><tr><td align="right">6.5 </td><td><a href="#%28part._composition%29" class="tocviewlink" data-pltdoc="x">Bilder zusammensetzen</a></td></tr><tr><td align="right">6.6 </td><td><a href="#%28part._from-pixels%29" class="tocviewlink" data-pltdoc="x">Bilder aus Pixeln konstruieren</a></td></tr></table></div></div></div><div class="tocsub"><div class="tocsubtitle">On this page:</div><table class="tocsublist" cellspacing="0"><tr><td><span class="tocsublinknumber">6.1<tt> </tt></span><a href="#%28part._.Bilder%29" class="tocsubseclink" data-pltdoc="x">Bilder</a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">image</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._empty-image%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">empty-<wbr></wbr>image</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image~3f%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">image?</span></span></a></td></tr><tr><td><span class="tocsublinknumber">6.2<tt> </tt></span><a href="#%28part._modes-colors%29" class="tocsubseclink" data-pltdoc="x">Modi und Farben</a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._mode%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">mode</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._octet%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">octet</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._rgb-color%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">rgb-<wbr></wbr>color</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._make-color%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">make-<wbr></wbr>color</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._color-red%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">color-<wbr></wbr>red</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._color-green%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">color-<wbr></wbr>green</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._color-blue%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">color-<wbr></wbr>blue</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._color~3f%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">color?</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-color%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">image-<wbr></wbr>color</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-color~3f%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">image-<wbr></wbr>color?</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._alpha-rgb-color%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">alpha-<wbr></wbr>rgb-<wbr></wbr>color</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._make-alpha-color%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">make-<wbr></wbr>alpha-<wbr></wbr>color</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._alpha-color-red%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">alpha-<wbr></wbr>color-<wbr></wbr>red</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._alpha-color-green%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">alpha-<wbr></wbr>color-<wbr></wbr>green</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._alpha-color-blue%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">alpha-<wbr></wbr>color-<wbr></wbr>blue</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._alpha-color-alpha%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">alpha-<wbr></wbr>color-<wbr></wbr>alpha</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._alpha-color~3f%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">alpha-<wbr></wbr>color?</span></span></a></td></tr><tr><td><span class="tocsublinknumber">6.3<tt> </tt></span><a href="#%28part._creational%29" class="tocsubseclink" data-pltdoc="x">Einfache geometrische Figuren</a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._rectangle%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">rectangle</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._circle%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">circle</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._ellipse%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">ellipse</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._triangle%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">triangle</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._line%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">line</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._text%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">text</span></span></a></td></tr><tr><td><span class="tocsublinknumber">6.4<tt> </tt></span><a href="#%28part._properties%29" class="tocsubseclink" data-pltdoc="x">Eigenschaften von Bildern</a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-width%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">image-<wbr></wbr>width</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-height%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">image-<wbr></wbr>height</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-inside~3f%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">image-<wbr></wbr>inside?</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._find-image%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">find-<wbr></wbr>image</span></span></a></td></tr><tr><td><span class="tocsublinknumber">6.5<tt> </tt></span><a href="#%28part._composition%29" class="tocsubseclink" data-pltdoc="x">Bilder zusammensetzen</a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._h-place%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">h-<wbr></wbr>place</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._v-place%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">v-<wbr></wbr>place</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._h-mode%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">h-<wbr></wbr>mode</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._v-mode%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">v-<wbr></wbr>mode</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._overlay%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">overlay</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._beside%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">beside</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._above%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">above</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._clip%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">clip</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._pad%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">pad</span></span></a></td></tr><tr><td><span class="tocsublinknumber">6.6<tt> </tt></span><a href="#%28part._from-pixels%29" class="tocsubseclink" data-pltdoc="x">Bilder aus Pixeln konstruieren</a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._color-list-~3eimage%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">color-<wbr></wbr>list-<wbr></wbr>>image</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-~3ecolor-list%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">image-<wbr></wbr>>color-<wbr></wbr>list</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._alpha-color-list-~3eimage%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">alpha-<wbr></wbr>color-<wbr></wbr>list-<wbr></wbr>>image</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-~3ealpha-color-list%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">image-<wbr></wbr>>alpha-<wbr></wbr>color-<wbr></wbr>list</span></span></a></td></tr></table></div></div><div class="maincolumn"><div class="main"><div class="navsettop"><span class="navleft"><form class="searchform"><input class="searchbox" style="color: #888;" type="text" value="...search manuals..." title="Enter a search string to search the manuals" onkeypress="return DoSearchKey(event, this, "6.1", "../");" onfocus="this.style.color="black"; this.style.textAlign="left"; if (this.value == "...search manuals...") this.value="";" onblur="if (this.value.match(/^ *$/)) { this.style.color="#888"; this.style.textAlign="center"; this.value="...search manuals..."; }"/></form> <a href="../index.html" title="up to the documentation top" data-pltdoc="x" onclick="return GotoPLTRoot("6.1");">top</a></span><span class="navright"> <a href="Konstruktionsanleitungen_1_bis_10.html" title="backward to "5 Konstruktionsanleitungen 1 bis 10"" data-pltdoc="x">← prev</a> <a href="index.html" title="up to "Sprachebenen und Material zu Die Macht der Abstraktion"" data-pltdoc="x">up</a> <a href="world.html" title="forward to "7 Animationen: "world.ss""" data-pltdoc="x">next →</a></span> </div><h3 x-source-module="(lib "deinprogramm/scribblings/deinprogramm.scrbl")" x-part-tag=""image"">6<tt> </tt><a name="(part._image)"></a>Bilder konstruieren: <span class="stt">"image.ss"</span><a name="(idx._(gentag._2._(lib._deinprogramm/scribblings/deinprogramm..scrbl)))"></a></h3><p>Note: This is documentation for the <span class="stt">"image.rkt"</span> teachpack that goes
with the German textbook
<span style="font-style: italic"><a href="http://www.deinprogramm.de/dmda/">Die Macht der
Abstraktion</a></span>.</p><p>Dieses Teachpack definiert Prozeduren für die Konstruktion von Bildern.
Einfache Bilder werden als geometrische Formen oder Bitmaps konstruiert.
Zusätzliche Prozeduren erlauben die Komposition von Bildern.</p><h4 x-source-module="(lib "deinprogramm/scribblings/deinprogramm.scrbl")" x-part-tag=""Bilder"">6.1<tt> </tt><a name="(part._.Bilder)"></a>Bilder</h4><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._image))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValDef RktValLink" data-pltdoc="x">image</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym">signature</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Ein <a name="(tech._bild)"></a><span style="font-style: italic">Bild</span> (Name: <span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span>) ist die Repräsentation eines Bildes.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._empty-image))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._empty-image%29%29" class="RktValDef RktValLink" data-pltdoc="x">empty-image</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Ein leeres Bild mit Breite und Höhe 0.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._image~3f))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image~3f%29%29" class="RktValDef RktValLink" data-pltdoc="x">image?</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=data-structure-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fprivate%252Fmisc..rkt%2529._any%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x">any</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=booleans.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._boolean%7E3f%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Der Aufruf <span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image~3f%29%29" class="RktValLink" data-pltdoc="x">image?</a></span><span class="stt"> </span><span class="RktSym">x</span><span class="RktPn">)</span> stellt fest, ob <span class="RktSym">x</span> ein Bild ist.</div></p><h4 x-source-module="(lib "deinprogramm/scribblings/deinprogramm.scrbl")" x-part-tag=""modes-colors"">6.2<tt> </tt><a name="(part._modes-colors)"></a>Modi und Farben</h4><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._mode))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._mode%29%29" class="RktValDef RktValLink" data-pltdoc="x">mode</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym">signature</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara"><span class="RktPn">(</span><span class="RktSym">one-of</span><span class="stt"> </span><span class="RktVal">"solid"</span><span class="stt"> </span><span class="RktVal">"outline"</span><span class="RktPn">)</span></div></p><p>Ein Modus (Name: <span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._mode%29%29" class="RktValLink" data-pltdoc="x">mode</a></span>) legt fest, ob die Darstellung einer Form diese füllt
oder nur einen Umriss zeichnet.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._octet))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._octet%29%29" class="RktValDef RktValLink" data-pltdoc="x">octet</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym">signature</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara"><span class="RktPn">(</span><span class="RktSym">combined</span><span class="stt"> </span><span class="RktSym">natural</span><span class="stt"> </span><span class="RktPn">(</span><span class="RktSym">predicate</span><span class="stt"> </span><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=lambda.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._lambda%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x">lambda</a></span><span class="stt"> </span><span class="RktPn">(</span><span class="RktSym">n</span><span class="RktPn">)</span><span class="stt"> </span><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=generic-numbers.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._%7E3c%7E3d%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x"><=</a></span><span class="stt"> </span><span class="RktSym">n</span><span class="stt"> </span><span class="RktVal">255</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></div></p><p>Ein Oktet (Name: <span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._octet%29%29" class="RktValLink" data-pltdoc="x">octet</a></span>) ist eine natürliche Zahl zwischen 0 und 255.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._rgb-color))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._rgb-color%29%29" class="RktValDef RktValLink" data-pltdoc="x">rgb-color</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym">signature</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Eine <a name="(tech._rgb._farbe)"></a><span style="font-style: italic">RGB-Farbe</span> ist eine Farbe (Name: <span class="RktSym">color</span>, die vom
Record-Konstruktor <span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._make-color%29%29" class="RktValLink" data-pltdoc="x">make-color</a></span> zurückgegeben wird:</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._make-color))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._make-color%29%29" class="RktValDef RktValLink" data-pltdoc="x">make-color</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._octet%29%29" class="RktValLink" data-pltdoc="x">octet</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._octet%29%29" class="RktValLink" data-pltdoc="x">octet</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._octet%29%29" class="RktValLink" data-pltdoc="x">octet</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._rgb-color%29%29" class="RktValLink" data-pltdoc="x">rgb-color</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Eine <a href="#%28tech._rgb._farbe%29" class="techoutside" data-pltdoc="x"><span class="techinside">RGB-Farbe</span></a> beschreibt eine Farbe mit den roten, blauen und grünen Anteilen,
also z.B. <span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._make-color%29%29" class="RktValLink" data-pltdoc="x">make-color</a></span><span class="stt"> </span><span class="RktVal">100</span><span class="stt"> </span><span class="RktVal">200</span><span class="stt"> </span><span class="RktVal">30</span><span class="RktPn">)</span>.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._color-red))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._color-red%29%29" class="RktValDef RktValLink" data-pltdoc="x">color-red</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">color</span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._octet%29%29" class="RktValLink" data-pltdoc="x">octet</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">liefert den Rot-Anteil einer RGB-Farbe.
</div><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._color-green))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._color-green%29%29" class="RktValDef RktValLink" data-pltdoc="x">color-green</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">color</span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._octet%29%29" class="RktValLink" data-pltdoc="x">octet</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">liefert den Grün-Anteil einer RGB-Farbe.
</div><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._color-blue))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._color-blue%29%29" class="RktValDef RktValLink" data-pltdoc="x">color-blue</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">color</span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._octet%29%29" class="RktValLink" data-pltdoc="x">octet</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">liefert den Blau-Anteil einer RGB-Farbe.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._color~3f))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._color~3f%29%29" class="RktValDef RktValLink" data-pltdoc="x">color?</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=data-structure-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fprivate%252Fmisc..rkt%2529._any%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x">any</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym">boolean</span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">stellt fest, ob ein Objekt eine <a href="#%28tech._rgb._farbe%29" class="techoutside" data-pltdoc="x"><span class="techinside">RGB-Farbe</span></a> ist.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._image-color))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-color%29%29" class="RktValDef RktValLink" data-pltdoc="x">image-color</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym">signature</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara"><span class="RktPn">(</span><span class="RktSym">mixed</span><span class="stt"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=strings.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._string%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">string</a></span><span class="stt"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._rgb-color%29%29" class="RktValLink" data-pltdoc="x">rgb-color</a></span><span class="RktPn">)</span></div></p><p>Eine <a name="(tech._farbe)"></a><span style="font-style: italic">Farbe</span> (Name: <span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-color%29%29" class="RktValLink" data-pltdoc="x">image-color</a></span>) ist eine Zeichenkette aus einer Farbbezeichnung
(z.B. <span class="RktVal">"blue"</span>) oder eine <a href="#%28tech._rgb._farbe%29" class="techoutside" data-pltdoc="x"><span class="techinside">RGB-Farbe</span></a>.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._image-color~3f))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-color~3f%29%29" class="RktValDef RktValLink" data-pltdoc="x">image-color?</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=data-structure-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fprivate%252Fmisc..rkt%2529._any%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x">any</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=booleans.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._boolean%7E3f%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara"> stellt fest, ob ein Objekt
eine <a href="#%28tech._farbe%29" class="techoutside" data-pltdoc="x"><span class="techinside">Farbe</span></a> ist.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._alpha-rgb-color))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._alpha-rgb-color%29%29" class="RktValDef RktValLink" data-pltdoc="x">alpha-rgb-color</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym">signature</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Eine <a name="(tech._alpha/rgb._farbe)"></a><span style="font-style: italic">Alpha/RGB-Farbe</span> ist eine Farbe (Name: <span class="RktSym">color</span>, die vom
Record-Konstruktor <span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._make-alpha-color%29%29" class="RktValLink" data-pltdoc="x">make-alpha-color</a></span> zurückgegeben wird:</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._make-alpha-color))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._make-alpha-color%29%29" class="RktValDef RktValLink" data-pltdoc="x">make-alpha-color</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._octet%29%29" class="RktValLink" data-pltdoc="x">octet</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._octet%29%29" class="RktValLink" data-pltdoc="x">octet</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._octet%29%29" class="RktValLink" data-pltdoc="x">octet</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._octet%29%29" class="RktValLink" data-pltdoc="x">octet</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym">alpha-color</span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Eine <a href="#%28tech._alpha%2Frgb._farbe%29" class="techoutside" data-pltdoc="x"><span class="techinside">Alpha/RGB-Farbe</span></a> beschreibt eine Farbe mit den Alpha-, roten,
blaue und grünen Anteilen, also z.B. <span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._make-color%29%29" class="RktValLink" data-pltdoc="x">make-color</a></span><span class="stt"> </span><span class="RktVal">50</span><span class="stt"> </span><span class="RktVal">100</span><span class="stt"> </span><span class="RktVal">200</span><span class="stt"> </span><span class="RktVal">30</span><span class="RktPn">)</span>. Der Alpha-Anteil beschreibt, wie durchsichtig die Farbe ist.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._alpha-color-red))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._alpha-color-red%29%29" class="RktValDef RktValLink" data-pltdoc="x">alpha-color-red</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">color</span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._octet%29%29" class="RktValLink" data-pltdoc="x">octet</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">liefert den Rot-Anteil einer RGB-Farbe.
</div><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._alpha-color-green))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._alpha-color-green%29%29" class="RktValDef RktValLink" data-pltdoc="x">alpha-color-green</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">color</span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._octet%29%29" class="RktValLink" data-pltdoc="x">octet</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">liefert den Grün-Anteil einer RGB-Farbe.
</div><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._alpha-color-blue))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._alpha-color-blue%29%29" class="RktValDef RktValLink" data-pltdoc="x">alpha-color-blue</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">color</span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._octet%29%29" class="RktValLink" data-pltdoc="x">octet</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">liefert den Blau-Anteil einer RGB-Farbe.
</div><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._alpha-color-alpha))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._alpha-color-alpha%29%29" class="RktValDef RktValLink" data-pltdoc="x">alpha-color-alpha</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">color</span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._octet%29%29" class="RktValLink" data-pltdoc="x">octet</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">liefert den Alpha-Anteil einer RGB-Farbe.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._alpha-color~3f))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._alpha-color~3f%29%29" class="RktValDef RktValLink" data-pltdoc="x">alpha-color?</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=data-structure-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fprivate%252Fmisc..rkt%2529._any%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x">any</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym">boolean</span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">stellt fest, ob ein Objekt eine <a href="#%28tech._alpha%2Frgb._farbe%29" class="techoutside" data-pltdoc="x"><span class="techinside">Alpha/RGB-Farbe</span></a> ist.</div></p><h4 x-source-module="(lib "deinprogramm/scribblings/deinprogramm.scrbl")" x-part-tag=""creational"">6.3<tt> </tt><a name="(part._creational)"></a>Einfache geometrische Figuren</h4><p>Die folgenden Prozeduren erzeugen Bilder mit einfachen geometrischen Formen:</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._rectangle))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._rectangle%29%29" class="RktValDef RktValLink" data-pltdoc="x">rectangle</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._mode%29%29" class="RktValLink" data-pltdoc="x">mode</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-color%29%29" class="RktValLink" data-pltdoc="x">image-color</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Der Aufruf <span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._rectangle%29%29" class="RktValLink" data-pltdoc="x">rectangle</a></span><span class="stt"> </span><span class="RktSym">w</span><span class="stt"> </span><span class="RktSym">h</span><span class="stt"> </span><span class="RktSym">m</span><span class="stt"> </span><span class="RktSym">c</span><span class="RktPn">)</span>
erzeugt ein Rechteck mit Breite <span class="RktSym">w</span> und Höhe <span class="RktSym">h</span>, gefüllt mit Modus
<span class="RktSym">m</span> und in Farbe <span class="RktSym">c</span>.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._circle))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._circle%29%29" class="RktValDef RktValLink" data-pltdoc="x">circle</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._mode%29%29" class="RktValLink" data-pltdoc="x">mode</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-color%29%29" class="RktValLink" data-pltdoc="x">image-color</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Der Aufruf <span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._circle%29%29" class="RktValLink" data-pltdoc="x">circle</a></span><span class="stt"> </span><span class="RktSym">r</span><span class="stt"> </span><span class="RktSym">m</span><span class="stt"> </span><span class="RktSym">c</span><span class="RktPn">)</span>
erzeugt einen Kreis oder eine Scheibe mit Radius <span class="RktSym">r</span>, gefüllt mit Modus
<span class="RktSym">m</span> und in Farbe <span class="RktSym">c</span>.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._ellipse))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._ellipse%29%29" class="RktValDef RktValLink" data-pltdoc="x">ellipse</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._mode%29%29" class="RktValLink" data-pltdoc="x">mode</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-color%29%29" class="RktValLink" data-pltdoc="x">image-color</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Der Aufruf <span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._ellipse%29%29" class="RktValLink" data-pltdoc="x">ellipse</a></span><span class="stt"> </span><span class="RktSym">w</span><span class="stt"> </span><span class="RktSym">h</span><span class="stt"> </span><span class="RktSym">m</span><span class="stt"> </span><span class="RktSym">c</span><span class="RktPn">)</span>
erzeugt eine Ellipse mit Breite <span class="RktSym">w</span> und Höhe <span class="RktSym">h</span>, gefüllt mit Modus
<span class="RktSym">m</span> und in Farbe <span class="RktSym">c</span>.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._triangle))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._triangle%29%29" class="RktValDef RktValLink" data-pltdoc="x">triangle</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">integer</span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._mode%29%29" class="RktValLink" data-pltdoc="x">mode</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-color%29%29" class="RktValLink" data-pltdoc="x">image-color</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Der Aufruf <span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._triangle%29%29" class="RktValLink" data-pltdoc="x">triangle</a></span><span class="stt"> </span><span class="RktSym">s</span><span class="stt"> </span><span class="RktSym">m</span><span class="stt"> </span><span class="RktSym">c</span><span class="RktPn">)</span>
erzeugt ein nach oben zeigendes gleichseitiges Dreieck, wobei
<span class="RktSym">s</span> die Seitenlänge angibt, gefüllt mit Modus
<span class="RktSym">m</span> und in Farbe <span class="RktSym">c</span>.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._line))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._line%29%29" class="RktValDef RktValLink" data-pltdoc="x">line</a></span></span></p></blockquote></td></tr><tr><td><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym">number</span><span class="hspace"> </span><span class="RktSym">number</span><span class="hspace"> </span><span class="RktSym">number</span><span class="hspace"> </span><span class="RktSym">number</span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-color%29%29" class="RktValLink" data-pltdoc="x">image-color</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="RktPn">)</span></td></tr></table></blockquote></div><div class="SIntrapara">Der Aufruf <span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._line%29%29" class="RktValLink" data-pltdoc="x">line</a></span><span class="stt"> </span><span class="RktSym">w</span><span class="stt"> </span><span class="RktSym">h</span><span class="stt"> </span><span class="RktSym">sx</span><span class="stt"> </span><span class="RktSym">sy</span><span class="stt"> </span><span class="RktSym">ex</span><span class="stt"> </span><span class="RktSym">ey</span><span class="stt"> </span><span class="RktSym">c</span><span class="RktPn">)</span>
erzeugt ein Bild mit einer farbigen Strecke, wobei <span class="RktSym">w</span> die Breite und <span class="RktSym">h</span> die Höhe des Bilds,
sowie <span class="RktSym">sx</span> die X- und <span class="RktSym">sx</span> die Y-Koordinate des Anfangspunkts und
<span class="RktSym">ex</span> die X- und <span class="RktSym">ey</span> die Y-Koordinate des Endpunkts angeben, gefüllt mit Modus
<span class="RktSym">m</span> und in Farbe <span class="RktSym">c</span>.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._text))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._text%29%29" class="RktValDef RktValLink" data-pltdoc="x">text</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=strings.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._string%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">string</a></span><span class="hspace"> </span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-color%29%29" class="RktValLink" data-pltdoc="x">image-color</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Der Aufruf <span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._text%29%29" class="RktValLink" data-pltdoc="x">text</a></span><span class="stt"> </span><span class="RktSym">s</span><span class="stt"> </span><span class="RktSym">f</span><span class="stt"> </span><span class="RktSym">c</span><span class="RktPn">)</span>
erzeugt ein Bild mit Text <span class="RktSym">s</span>,
wobei die Buchstaben die Größe <span class="RktSym">f</span> haben, in Farbe <span class="RktSym">c</span></div></p><p>Außerdem können beliebige Bitmap-Bilder in ein Scheme-Programm
eingeklebt werden.</p><h4 x-source-module="(lib "deinprogramm/scribblings/deinprogramm.scrbl")" x-part-tag=""properties"">6.4<tt> </tt><a name="(part._properties)"></a>Eigenschaften von Bildern</h4><p>Zwei Eigenschaften von Bildern sind für ihre Manipulation nützlich,
nämlich Breite und Höhe:</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._image-width))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-width%29%29" class="RktValDef RktValLink" data-pltdoc="x">image-width</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym">natural</span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">liefert die Breite von <span class="RktSym">i</span> in Pixeln.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._image-height))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-height%29%29" class="RktValDef RktValLink" data-pltdoc="x">image-height</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym">natural</span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">liefert die Höhe von <span class="RktSym">i</span> in Pixeln.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._image-inside~3f))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-inside~3f%29%29" class="RktValDef RktValLink" data-pltdoc="x">image-inside?</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym">boolean</span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Der Aufruf <span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-inside~3f%29%29" class="RktValLink" data-pltdoc="x">image-inside?</a></span><span class="stt"> </span><span class="RktSym">i1</span><span class="stt"> </span><span class="RktSym">i2</span><span class="RktPn">)</span> stellt fest, ob das Bild
<span class="RktSym">i2</span> im Bild <span class="RktSym">i1</span> enthalten ist.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._find-image))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._find-image%29%29" class="RktValDef RktValLink" data-pltdoc="x">find-image</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym">posn</span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Der Aufruf <span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._find-image%29%29" class="RktValLink" data-pltdoc="x">find-image</a></span><span class="stt"> </span><span class="RktSym">i1</span><span class="stt"> </span><span class="RktSym">i2</span><span class="RktPn">)</span> findet die Position von <span class="RktSym">i2</span>
im Bild <span class="RktSym">i1</span> (in dem es vorkommen muss).</div></p><h4 x-source-module="(lib "deinprogramm/scribblings/deinprogramm.scrbl")" x-part-tag=""composition"">6.5<tt> </tt><a name="(part._composition)"></a>Bilder zusammensetzen</h4><p>The nächste Gruppe von Prozeduren baut aus Bildern neue Bilder:</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._h-place))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._h-place%29%29" class="RktValDef RktValLink" data-pltdoc="x">h-place</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym">signature</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara"><span class="RktPn">(</span><span class="RktSym">mixed</span><span class="stt"> </span><span class="RktSym">integer</span><span class="stt"> </span><span class="RktPn">(</span><span class="RktSym">one-of</span><span class="stt"> </span><span class="RktVal">"left"</span><span class="stt"> </span><span class="RktVal">"right"</span><span class="stt"> </span><span class="RktVal">"center"</span><span class="RktPn">)</span><span class="RktPn">)</span></div></p><p>Eine <a name="(tech._horizontale._positionsangabe)"></a><span style="font-style: italic">horizontale Positionsangabe</span> (Name: <span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._h-place%29%29" class="RktValLink" data-pltdoc="x">h-place</a></span>)
gibt an, wie zwei Bilder horizontal zueinander positioniert werden</p><p>Im ersten Fall, wenn es sich um eine Zahl <span class="RktSym">x</span> handelt, wird das
zweite Bild <span class="RktSym">x</span> Pixel vom linken Rand auf das erste gelegt.
Die drei Fälle mit Zeichenketten sagen, daß die Bilder am linken Rand
bzw. am rechten Rand bündig plaziert werden, bzw. das zweite Bild
horizontal in die Mitte des ersten gesetzt wird.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._v-place))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._v-place%29%29" class="RktValDef RktValLink" data-pltdoc="x">v-place</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym">signature</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara"><span class="RktPn">(</span><span class="RktSym">mixed</span><span class="stt"> </span><span class="RktSym">integer</span><span class="stt"> </span><span class="RktPn">(</span><span class="RktSym">one-of</span><span class="stt"> </span><span class="RktVal">"top"</span><span class="stt"> </span><span class="RktVal">"bottom"</span><span class="stt"> </span><span class="RktVal">"center"</span><span class="RktPn">)</span><span class="RktPn">)</span></div></p><p>Eine <a name="(tech._vertikale._positionsangabe)"></a><span style="font-style: italic">vertikale Positionsangabe</span> (Name: <span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._v-place%29%29" class="RktValLink" data-pltdoc="x">v-place</a></span>)
gibt an, wie zwei Bilder vertikal zueinander positioniert werden</p><p>Im ersten Fall, wenn es sich um eine Zahl <span class="RktSym">y</span> handelt, wird das
zweite Bild <span class="RktSym">y</span> Pixel vom oberen Rand auf das erste gelegt.
Die drei Fälle mit Zeichenketten sagen, daß die Bilder am oberen Rand
bzw. am unteren Rand bündig plaziert werden, bzw. das zweite Bild
vertikal in die Mitte des ersten gesetzt wird.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._h-mode))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._h-mode%29%29" class="RktValDef RktValLink" data-pltdoc="x">h-mode</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym">signature</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara"><span class="RktPn">(</span><span class="RktSym">one-of</span><span class="stt"> </span><span class="RktVal">"left"</span><span class="stt"> </span><span class="RktVal">"right"</span><span class="stt"> </span><span class="RktVal">"center"</span><span class="RktPn">)</span>
Eine <a name="(tech._horizontale._justierungsangabe)"></a><span style="font-style: italic">horizontale Justierungsangabe</span> (Name: <span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._h-mode%29%29" class="RktValLink" data-pltdoc="x">h-mode</a></span>)
gibt an, ob zwei Bilder, die übereinander angeordnet werden, entlang der linken
Kante, der rechten Kante oder der Mitte angeordnet werden.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._v-mode))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._v-mode%29%29" class="RktValDef RktValLink" data-pltdoc="x">v-mode</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym">signature</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara"><span class="RktPn">(</span><span class="RktSym">one-of</span><span class="stt"> </span><span class="RktVal">"top"</span><span class="stt"> </span><span class="RktVal">"bottom"</span><span class="stt"> </span><span class="RktVal">"center"</span><span class="RktPn">)</span></div></p><p>Eine <a name="(tech._vertikale._justierungsangabe)"></a><span style="font-style: italic">vertikale Justierungsangabe</span> (Name: <span class="RktSym">V-mode</span>)
gibt an, ob zwei Bilder, die nebenander angeordnet werden, entlang der
oberen Kante, der untern Kante oder der Mitte angeordnet werden.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._overlay))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._overlay%29%29" class="RktValDef RktValLink" data-pltdoc="x">overlay</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._h-place%29%29" class="RktValLink" data-pltdoc="x">h-place</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._v-place%29%29" class="RktValLink" data-pltdoc="x">v-place</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Der Aufruf <span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._overlay%29%29" class="RktValLink" data-pltdoc="x">overlay</a></span><span class="stt"> </span><span class="RktSym">img</span><span class="stt"> </span><span class="RktSym">other</span><span class="stt"> </span><span class="RktSym">h</span><span class="stt"> </span><span class="RktSym">v</span><span class="RktPn">)</span>
legt zweite Bild <span class="RktSym">other</span> auf das erste <span class="RktSym">img</span>. Die beiden anderen Argumente geben an, wie
die beiden Bilder zueinander positioniert werden.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._beside))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._beside%29%29" class="RktValDef RktValLink" data-pltdoc="x">beside</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._v-mode%29%29" class="RktValLink" data-pltdoc="x">v-mode</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Der Aufruf <span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._beside%29%29" class="RktValLink" data-pltdoc="x">beside</a></span><span class="stt"> </span><span class="RktSym">img</span><span class="stt"> </span><span class="RktSym">other</span><span class="stt"> </span><span class="RktSym">v</span><span class="RktPn">)</span>
ordnet die beiden Bilder entsprechend des <span class="RktSym">v</span>-Arguments
nebeneinander an.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._above))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._above%29%29" class="RktValDef RktValLink" data-pltdoc="x">above</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._h-mode%29%29" class="RktValLink" data-pltdoc="x">h-mode</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Der Aufruf <span class="RktPn">(</span><span class="RktSym">img</span><span class="stt"> </span><span class="RktSym">other</span><span class="stt"> </span><span class="RktSym">h</span><span class="stt"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="stt"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="RktPn">)</span>
ordnet die beiden Bilder entsprechend des <span class="RktSym">h</span>-Arguments
übereinander an.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._clip))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._clip%29%29" class="RktValDef RktValLink" data-pltdoc="x">clip</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="hspace"> </span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Der Aufruf <span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._clip%29%29" class="RktValLink" data-pltdoc="x">clip</a></span><span class="stt"> </span><span class="RktSym">img</span><span class="stt"> </span><span class="RktSym">x</span><span class="stt"> </span><span class="RktSym">y</span><span class="stt"> </span><span class="RktSym">w</span><span class="stt"> </span><span class="RktSym">h</span><span class="RktPn">)</span>
liefert das Teilrechteck des Bildes <span class="RktSym">img</span>
bei (<span class="RktSym">x</span>, <span class="RktSym">y</span>), Breite <span class="RktSym">w</span> und Höhe <span class="RktSym">h</span>.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._pad))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._pad%29%29" class="RktValDef RktValLink" data-pltdoc="x">pad</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="hspace"> </span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Der Aufruf <span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._pad%29%29" class="RktValLink" data-pltdoc="x">pad</a></span><span class="stt"> </span><span class="RktSym">img</span><span class="stt"> </span><span class="RktSym">l</span><span class="stt"> </span><span class="RktSym">r</span><span class="stt"> </span><span class="RktSym">t</span><span class="stt"> </span><span class="RktSym">b</span><span class="RktPn">)</span>
fügt an den Seiten von <span class="RktSym">img</span> noch transparenten Leerraum an:
<span class="RktSym">l</span> Pixel links, <span class="RktSym">r</span> Pixel rechts, <span class="RktSym">t</span> Pixel oben und
<span class="RktSym">b</span> Pixel unten.</div></p><h4 x-source-module="(lib "deinprogramm/scribblings/deinprogramm.scrbl")" x-part-tag=""from-pixels"">6.6<tt> </tt><a name="(part._from-pixels)"></a>Bilder aus Pixeln konstruieren</h4><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._color-list-~3eimage))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._color-list-~3eimage%29%29" class="RktValDef RktValLink" data-pltdoc="x">color-list->image</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktPn">(</span><span class="RktSym">list-of</span><span class="hspace"> </span><span class="RktSym">color</span><span class="RktPn">)</span><span class="hspace"> </span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Der Aufruf <span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._color-list-~3eimage%29%29" class="RktValLink" data-pltdoc="x">color-list->image</a></span><span class="stt"> </span><span class="RktSym">lis</span><span class="stt"> </span><span class="RktSym">w</span><span class="stt"> </span><span class="RktSym">h</span><span class="RktPn">)</span> stellt ein Bild mit
Breite <span class="RktSym">w</span> und Höhe <span class="RktSym">h</span> her, in dem die Pixel die
Farben aus der Liste <span class="RktSym">lis</span> (welche die Länge <span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=generic-numbers.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._%252A%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">*</a></span><span class="stt"> </span><span class="RktSym">w</span><span class="stt"> </span><span class="RktSym">h</span><span class="RktPn">)</span>
haben muß) haben.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._image-~3ecolor-list))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-~3ecolor-list%29%29" class="RktValDef RktValLink" data-pltdoc="x">image->color-list</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">list-of</span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._rgb-color%29%29" class="RktValLink" data-pltdoc="x">rgb-color</a></span><span class="RktPn">)</span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Diese Prozedur liefert eine Liste der RGB-Farben der Pixel eines Bildes.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._alpha-color-list-~3eimage))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._alpha-color-list-~3eimage%29%29" class="RktValDef RktValLink" data-pltdoc="x">alpha-color-list->image</a></span></span></p></blockquote></td></tr><tr><td><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktPn">(</span><span class="RktSym">list-of</span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._alpha-rgb-color%29%29" class="RktValLink" data-pltdoc="x">alpha-rgb-color</a></span><span class="RktPn">)</span><span class="hspace"> </span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym">natural</span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="RktPn">)</span></td></tr></table></blockquote></div><div class="SIntrapara">Der Aufruf <span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._color-list-~3eimage%29%29" class="RktValLink" data-pltdoc="x">color-list->image</a></span><span class="stt"> </span><span class="RktSym">lis</span><span class="stt"> </span><span class="RktSym">w</span><span class="stt"> </span><span class="RktSym">h</span><span class="RktPn">)</span> stellt ein Bild mit
Breite <span class="RktSym">w</span> und Höhe <span class="RktSym">h</span> her, in dem die Pixel die
Farben aus der Liste <span class="RktSym">lis</span> (welche die Länge <span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=generic-numbers.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._%252A%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">*</a></span><span class="stt"> </span><span class="RktSym">w</span><span class="stt"> </span><span class="RktSym">h</span><span class="RktPn">)</span>
haben muß) haben.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._deinprogramm/image..rkt)._image-~3ealpha-color-list))"></a><span title="Provided from: teachpack/deinprogramm/image | Package: deinprogramm"><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image-~3ealpha-color-list%29%29" class="RktValDef RktValLink" data-pltdoc="x">image->alpha-color-list</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._image%29%29" class="RktValLink" data-pltdoc="x">image</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=function-contracts.html%23%2528form._%2528%2528lib._racket%252Fcontract%252Fbase..rkt%2529._-%7E3e%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x"><span class="nobreak">-></span></a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">list-of</span><span class="hspace"> </span><span class="RktSym"><a href="#%28def._%28%28lib._deinprogramm%2Fimage..rkt%29._rgb-color%29%29" class="RktValLink" data-pltdoc="x">rgb-color</a></span><span class="RktPn">)</span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Diese Prozedur liefert eine Liste der Alpha/RGB-Farben der Pixel
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