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<div id=Content><div class="CFile"><div class=CTopic id=MainTopic><h1 class=CTitle><a name="Color_Quantization"></a>Color Quantization</h1><div class=CBody><p>Functions for truecolor to palette conversion</p><!--START_ND_SUMMARY--><div class=Summary><div class=STitle>Summary</div><div class=SBorder><table border=0 cellspacing=0 cellpadding=0 class=STable><tr class="SMain"><td class=SEntry><a href="#Color_Quantization" >Color Quantization</a></td><td class=SDescription>Functions for truecolor to palette conversion</td></tr><tr class="SGroup"><td class=SEntry><a href="#Functions" >Functions</a></td><td class=SDescription></td></tr><tr class="SFunction SIndent1 SMarked"><td class=SEntry><a href="#gdImageTrueColorToPaletteSetMethod" id=link1 onMouseOver="ShowTip(event, 'tt1', 'link1')" onMouseOut="HideTip('tt1')">gdImageTrueColorToPaletteSetMethod</a></td><td class=SDescription>Selects the quantization method</td></tr><tr class="SFunction SIndent1"><td class=SEntry><a href="#gdImageTrueColorToPaletteSetQuality" id=link2 onMouseOver="ShowTip(event, 'tt2', 'link2')" onMouseOut="HideTip('tt2')">gdImageTrueColorToPaletteSetQuality</a></td><td class=SDescription>Chooses a quality range for quantization</td></tr><tr class="SFunction SIndent1 SMarked"><td class=SEntry><a href="#gdImageCreatePaletteFromTrueColor" id=link3 onMouseOver="ShowTip(event, 'tt3', 'link3')" onMouseOut="HideTip('tt3')">gdImageCreatePaletteFromTrueColor</a></td><td class=SDescription>Creates a new palette image from a truecolor image</td></tr><tr class="SFunction SIndent1"><td class=SEntry><a href="#gdImageTrueColorToPalette" id=link4 onMouseOver="ShowTip(event, 'tt4', 'link4')" onMouseOut="HideTip('tt4')">gdImageTrueColorToPalette</a></td><td class=SDescription>Converts a truecolor image to a palette image</td></tr></table></div></div><!--END_ND_SUMMARY--></div></div></div>
<div class="CGroup"><div class=CTopic><h3 class=CTitle><a name="Functions"></a>Functions</h3></div></div>
<div class="CFunction"><div class=CTopic><h3 class=CTitle><a name="gdImageTrueColorToPaletteSetMethod"></a>gdImageTrueColorToPaletteSetMethod</h3><div class=CBody><blockquote><table border=0 cellspacing=0 cellpadding=0 class="Prototype"><tr><td><table border=0 cellspacing=0 cellpadding=0><tr><td class="PBeforeParameters prettyprint "nowrap>int gdImageTrueColorToPaletteSetMethod (</td><td class="PType prettyprint " nowrap>gdImagePtr </td><td class="PParameter prettyprint " nowrap>im,</td></tr><tr><td></td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>method,</td></tr><tr><td></td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>speed</td><td class="PAfterParameters prettyprint "nowrap>)</td></tr></table></td></tr></table></blockquote><p>Selects the quantization method</p><p>That quantization method is used for all subsequent <a href="#gdImageTrueColorToPalette" class=LFunction id=link5 onMouseOver="ShowTip(event, 'tt4', 'link5')" onMouseOut="HideTip('tt4')">gdImageTrueColorToPalette</a> and <a href="#gdImageCreatePaletteFromTrueColor" class=LFunction id=link6 onMouseOver="ShowTip(event, 'tt3', 'link6')" onMouseOut="HideTip('tt3')">gdImageCreatePaletteFromTrueColor</a> calls.</p><h4 class=CHeading>Parameters</h4><table border=0 cellspacing=0 cellpadding=0 class=CDescriptionList><tr><td class=CDLEntry>im</td><td class=CDLDescription>The image.</td></tr><tr><td class=CDLEntry>method</td><td class=CDLDescription>The quantization method, see <a href="gd-h.html#gdPaletteQuantizationMethod" class=LType >gdPaletteQuantizationMethod</a>.</td></tr><tr><td class=CDLEntry>speed</td><td class=CDLDescription>The quantization speed between 1 (highest quality) and 10 (fastest). 0 selects a method-specific default (recommended).</td></tr></table><h4 class=CHeading>Returns</h4><p>Zero if the given method is invalid or not available; non-zero otherwise.</p><h4 class=CHeading>See also</h4><ul><li><a href="#gdImageTrueColorToPaletteSetQuality" class=LFunction id=link7 onMouseOver="ShowTip(event, 'tt2', 'link7')" onMouseOut="HideTip('tt2')">gdImageTrueColorToPaletteSetQuality</a></li></ul></div></div></div>
<div class="CFunction"><div class=CTopic><h3 class=CTitle><a name="gdImageTrueColorToPaletteSetQuality"></a>gdImageTrueColorToPaletteSetQuality</h3><div class=CBody><blockquote><table border=0 cellspacing=0 cellpadding=0 class="Prototype"><tr><td><table border=0 cellspacing=0 cellpadding=0><tr><td class="PBeforeParameters prettyprint "nowrap>void gdImageTrueColorToPaletteSetQuality (</td><td class="PType prettyprint " nowrap>gdImagePtr </td><td class="PParameter prettyprint " nowrap>im,</td></tr><tr><td></td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>min_quality,</td></tr><tr><td></td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>max_quality</td><td class="PAfterParameters prettyprint "nowrap>)</td></tr></table></td></tr></table></blockquote><p>Chooses a quality range for quantization</p><p>That quality range is used in all subsequent calls to <a href="#gdImageTrueColorToPalette" class=LFunction id=link8 onMouseOver="ShowTip(event, 'tt4', 'link8')" onMouseOut="HideTip('tt4')">gdImageTrueColorToPalette</a> and <a href="#gdImageCreatePaletteFromTrueColor" class=LFunction id=link9 onMouseOver="ShowTip(event, 'tt3', 'link9')" onMouseOut="HideTip('tt3')">gdImageCreatePaletteFromTrueColor</a> if the quantization method is <a href="gd-h.html#GD_QUANT_LIQ" class=LConstant id=link10 onMouseOver="ShowTip(event, 'tt5', 'link10')" onMouseOut="HideTip('tt5')">GD_QUANT_LIQ</a>.</p><h4 class=CHeading>Parameters</h4><table border=0 cellspacing=0 cellpadding=0 class=CDescriptionList><tr><td class=CDLEntry>im</td><td class=CDLDescription>The image.</td></tr><tr><td class=CDLEntry>min_quality</td><td class=CDLDescription>The minimum quality in range 1-100 (1 = ugly, 100 = perfect). If the palette cannot represent the image with at least min_quality, then no conversion is done.</td></tr><tr><td class=CDLEntry>max_quality</td><td class=CDLDescription>The maximum quality in range 1-100 (1 = ugly, 100 = perfect), which must be higher than the min_quality. If the palette can represent the image with a quality better than max_quality, then fewer colors than requested will be used.</td></tr></table></div></div></div>
<div class="CFunction"><div class=CTopic><h3 class=CTitle><a name="gdImageCreatePaletteFromTrueColor"></a>gdImageCreatePaletteFromTrueColor</h3><div class=CBody><blockquote><table border=0 cellspacing=0 cellpadding=0 class="Prototype"><tr><td><table border=0 cellspacing=0 cellpadding=0><tr><td class="PBeforeParameters prettyprint "nowrap>gdImagePtr gdImageCreatePaletteFromTrueColor (</td><td class="PType prettyprint " nowrap>gdImagePtr </td><td class="PParameter prettyprint " nowrap>im,</td></tr><tr><td></td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>dither,</td></tr><tr><td></td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>colorsWanted</td><td class="PAfterParameters prettyprint "nowrap>)</td></tr></table></td></tr></table></blockquote><p>Creates a new palette image from a truecolor image</p><h4 class=CHeading>Parameters</h4><table border=0 cellspacing=0 cellpadding=0 class=CDescriptionList><tr><td class=CDLEntry>im</td><td class=CDLDescription>The image.</td></tr><tr><td class=CDLEntry>dither</td><td class=CDLDescription>Whether dithering should be applied.</td></tr><tr><td class=CDLEntry>colorsWanted</td><td class=CDLDescription>The number of desired palette entries.</td></tr></table><h4 class=CHeading>Returns</h4><p>A newly create palette image; NULL on failure.</p><h4 class=CHeading>See also</h4><ul><li><a href="#gdImageCreatePaletteFromTrueColor" class=LFunction id=link11 onMouseOver="ShowTip(event, 'tt3', 'link11')" onMouseOut="HideTip('tt3')">gdImageCreatePaletteFromTrueColor</a></li><li><a href="#gdImageTrueColorToPaletteSetMethod" class=LFunction id=link12 onMouseOver="ShowTip(event, 'tt1', 'link12')" onMouseOut="HideTip('tt1')">gdImageTrueColorToPaletteSetMethod</a></li><li><a href="gd_nnquant-c.html#gdImageNeuQuant" class=LFunction id=link13 onMouseOver="ShowTip(event, 'tt6', 'link13')" onMouseOut="HideTip('tt6')">gdImageNeuQuant</a></li></ul></div></div></div>
<div class="CFunction"><div class=CTopic><h3 class=CTitle><a name="gdImageTrueColorToPalette"></a>gdImageTrueColorToPalette</h3><div class=CBody><blockquote><table border=0 cellspacing=0 cellpadding=0 class="Prototype"><tr><td><table border=0 cellspacing=0 cellpadding=0><tr><td class="PBeforeParameters prettyprint "nowrap>int gdImageTrueColorToPalette (</td><td class="PType prettyprint " nowrap>gdImagePtr </td><td class="PParameter prettyprint " nowrap>im,</td></tr><tr><td></td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>dither,</td></tr><tr><td></td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>colorsWanted</td><td class="PAfterParameters prettyprint "nowrap>)</td></tr></table></td></tr></table></blockquote><p>Converts a truecolor image to a palette image</p><h4 class=CHeading>Parameters</h4><table border=0 cellspacing=0 cellpadding=0 class=CDescriptionList><tr><td class=CDLEntry>im</td><td class=CDLDescription>The image.</td></tr><tr><td class=CDLEntry>dither</td><td class=CDLDescription>Whether dithering should be applied.</td></tr><tr><td class=CDLEntry>colorsWanted</td><td class=CDLDescription>The number of desired palette entries.</td></tr></table><h4 class=CHeading>Returns</h4><p>Non-zero if the conversion succeeded, zero otherwise.</p><h4 class=CHeading>See also</h4><ul><li><a href="#gdImageCreatePaletteFromTrueColor" class=LFunction id=link14 onMouseOver="ShowTip(event, 'tt3', 'link14')" onMouseOut="HideTip('tt3')">gdImageCreatePaletteFromTrueColor</a></li><li><a href="#gdImageTrueColorToPaletteSetMethod" class=LFunction id=link15 onMouseOver="ShowTip(event, 'tt1', 'link15')" onMouseOut="HideTip('tt1')">gdImageTrueColorToPaletteSetMethod</a></li><li><a href="gd-c.html#gdImagePaletteToTrueColor" class=LFunction id=link16 onMouseOver="ShowTip(event, 'tt7', 'link16')" onMouseOut="HideTip('tt7')">gdImagePaletteToTrueColor</a></li></ul></div></div></div>
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<div class=CToolTip id="tt1"><div class=CFunction><blockquote><table border=0 cellspacing=0 cellpadding=0 class="Prototype"><tr><td><table border=0 cellspacing=0 cellpadding=0><tr><td class="PBeforeParameters prettyprint "nowrap>int gdImageTrueColorToPaletteSetMethod (</td><td class="PType prettyprint " nowrap>gdImagePtr </td><td class="PParameter prettyprint " nowrap>im,</td></tr><tr><td></td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>method,</td></tr><tr><td></td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>speed</td><td class="PAfterParameters prettyprint "nowrap>)</td></tr></table></td></tr></table></blockquote>Selects the quantization method</div></div><div class=CToolTip id="tt2"><div class=CFunction><blockquote><table border=0 cellspacing=0 cellpadding=0 class="Prototype"><tr><td><table border=0 cellspacing=0 cellpadding=0><tr><td class="PBeforeParameters prettyprint "nowrap>void gdImageTrueColorToPaletteSetQuality (</td><td class="PType prettyprint " nowrap>gdImagePtr </td><td class="PParameter prettyprint " nowrap>im,</td></tr><tr><td></td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>min_quality,</td></tr><tr><td></td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>max_quality</td><td class="PAfterParameters prettyprint "nowrap>)</td></tr></table></td></tr></table></blockquote>Chooses a quality range for quantization</div></div><div class=CToolTip id="tt3"><div class=CFunction><blockquote><table border=0 cellspacing=0 cellpadding=0 class="Prototype"><tr><td><table border=0 cellspacing=0 cellpadding=0><tr><td class="PBeforeParameters prettyprint "nowrap>gdImagePtr gdImageCreatePaletteFromTrueColor (</td><td class="PType prettyprint " nowrap>gdImagePtr </td><td class="PParameter prettyprint " nowrap>im,</td></tr><tr><td></td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>dither,</td></tr><tr><td></td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>colorsWanted</td><td class="PAfterParameters prettyprint "nowrap>)</td></tr></table></td></tr></table></blockquote>Creates a new palette image from a truecolor image</div></div><div class=CToolTip id="tt4"><div class=CFunction><blockquote><table border=0 cellspacing=0 cellpadding=0 class="Prototype"><tr><td><table border=0 cellspacing=0 cellpadding=0><tr><td class="PBeforeParameters prettyprint "nowrap>int gdImageTrueColorToPalette (</td><td class="PType prettyprint " nowrap>gdImagePtr </td><td class="PParameter prettyprint " nowrap>im,</td></tr><tr><td></td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>dither,</td></tr><tr><td></td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>colorsWanted</td><td class="PAfterParameters prettyprint "nowrap>)</td></tr></table></td></tr></table></blockquote>Converts a truecolor image to a palette image</div></div><div class=CToolTip id="tt5"><div class=CConstant>A combination of algorithms used in libimagequant aiming for the highest quality at cost of speed.</div></div><div class=CToolTip id="tt6"><div class=CFunction><blockquote><table border=0 cellspacing=0 cellpadding=0 class="Prototype"><tr><td><table border=0 cellspacing=0 cellpadding=0><tr><td class="PBeforeParameters prettyprint "nowrap>gdImagePtr gdImageNeuQuant(</td><td class="PTypePrefix prettyprint " nowrap></td><td class="PType prettyprint " nowrap>gdImagePtr </td><td class="PParameter prettyprint " nowrap>im,</td></tr><tr><td></td><td class="PTypePrefix prettyprint " nowrap>const </td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>max_color,</td></tr><tr><td></td><td class="PTypePrefix prettyprint " nowrap></td><td class="PType prettyprint " nowrap>int </td><td class="PParameter prettyprint " nowrap>sample_factor</td><td class="PAfterParameters prettyprint "nowrap>)</td></tr></table></td></tr></table></blockquote>Creates a new palette image from a truecolor image</div></div><div class=CToolTip id="tt7"><div class=CFunction><blockquote><table border=0 cellspacing=0 cellpadding=0 class="Prototype"><tr><td><table border=0 cellspacing=0 cellpadding=0><tr><td class="PBeforeParameters prettyprint "nowrap>int gdImagePaletteToTrueColor(</td><td class="PType prettyprint " nowrap>gdImagePtr </td><td class="PParameter prettyprint " nowrap>src</td><td class="PAfterParameters prettyprint "nowrap>)</td></tr></table></td></tr></table></blockquote>Convert a palette image to true color</div></div><!--END_ND_TOOLTIPS-->
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