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Get the dominant color of an image

function get_dominant_color($image)
    $i = imagecreatefromjpeg($image); // eg: "image.jpg"

    for ($x = 0; $x < imagesx($i); $x++)
        for ($y = 0; $y < imagesy($i); $y++)
            $rgb = imagecolorat($i, $x, $y);
            $r = ($rgb >> 16) & 0xFF;
            $g = ($rgb >> 8) & 0xFF;
            $b = $rgb & 0xFF;
            $rTotal += $r;
            $gTotal += $g;
            $bTotal += $b;

    $rAverage = round($rTotal / $total);
    $gAverage = round($gTotal / $total);
    $bAverage = round($bTotal / $total);

* To boost up the colors in a photo, get its dominant color,
* then, with a tool like PhotoShop or the GIMP, create a new
* layer filled with that color, then invert it and set the
* blend mode to "Overlay".
<table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><a href="#L-1"> 1</a> <a href="#L-2"> 2</a> <a href="#L-3"> 3</a> <a href="#L-4"> 4</a> <a href="#L-5"> 5</a> <a href="#L-6"> 6</a> <a href="#L-7"> 7</a> <a href="#L-8"> 8</a> <a href="#L-9"> 9</a> <a href="#L-10">10</a> <a href="#L-11">11</a> <a href="#L-12">12</a> <a href="#L-13">13</a> <a href="#L-14">14</a> <a href="#L-15">15</a> <a href="#L-16">16</a> <a href="#L-17">17</a> <a href="#L-18">18</a> <a href="#L-19">19</a> <a href="#L-20">20</a> <a href="#L-21">21</a> <a href="#L-22">22</a> <a href="#L-23">23</a> <a href="#L-24">24</a> <a href="#L-25">25</a> <a href="#L-26">26</a> <a href="#L-27">27</a> <a href="#L-28">28</a> <a href="#L-29">29</a> <a href="#L-30">30</a> <a href="#L-31">31</a> <a href="#L-32">32</a> <a href="#L-33">33</a> <a href="#L-34">34</a></pre></div></td><td class="code"><div class="highlight"><pre><span></span><span id="L-1"><a name="L-1"></a><span class="x">function get_dominant_color($image)</span> </span><span id="L-2"><a name="L-2"></a><span class="x">{</span> </span><span id="L-3"><a name="L-3"></a><span class="x"> $i = imagecreatefromjpeg($image); // eg: &quot;image.jpg&quot;</span> </span><span id="L-4"><a name="L-4"></a> </span><span id="L-5"><a name="L-5"></a><span class="x"> for ($x = 0; $x &lt; imagesx($i); $x++)</span> </span><span id="L-6"><a name="L-6"></a><span class="x"> {</span> </span><span id="L-7"><a name="L-7"></a><span class="x"> for ($y = 0; $y &lt; imagesy($i); $y++)</span> </span><span id="L-8"><a name="L-8"></a><span class="x"> {</span> </span><span id="L-9"><a name="L-9"></a><span class="x"> $rgb = imagecolorat($i, $x, $y);</span> </span><span id="L-10"><a name="L-10"></a><span class="x"> $r = ($rgb &gt;&gt; 16) &amp; 0xFF;</span> </span><span id="L-11"><a name="L-11"></a><span class="x"> $g = ($rgb &gt;&gt; 8) &amp; 0xFF;</span> </span><span id="L-12"><a name="L-12"></a><span class="x"> $b = $rgb &amp; 0xFF;</span> </span><span id="L-13"><a name="L-13"></a><span class="x"> $rTotal += $r;</span> </span><span id="L-14"><a name="L-14"></a><span class="x"> $gTotal += $g;</span> </span><span id="L-15"><a name="L-15"></a><span class="x"> $bTotal += $b;</span> </span><span id="L-16"><a name="L-16"></a><span class="x"> $total++;</span> </span><span id="L-17"><a name="L-17"></a><span class="x"> }</span> </span><span id="L-18"><a name="L-18"></a><span class="x"> }</span> </span><span id="L-19"><a name="L-19"></a> </span><span id="L-20"><a name="L-20"></a><span class="x"> $rAverage = round($rTotal / $total);</span> </span><span id="L-21"><a name="L-21"></a><span class="x"> $gAverage = round($gTotal / $total);</span> </span><span id="L-22"><a name="L-22"></a><span class="x"> $bAverage = round($bTotal / $total);</span> </span><span id="L-23"><a name="L-23"></a><span class="x">}</span> </span><span id="L-24"><a name="L-24"></a> </span><span id="L-25"><a name="L-25"></a> </span><span id="L-26"><a name="L-26"></a> </span><span id="L-27"><a name="L-27"></a><span class="x">/*************</span> </span><span id="L-28"><a name="L-28"></a><span class="x">* COOL TIP:</span> </span><span id="L-29"><a name="L-29"></a><span class="x">*</span> </span><span id="L-30"><a name="L-30"></a><span class="x">* To boost up the colors in a photo, get its dominant color,</span> </span><span id="L-31"><a name="L-31"></a><span class="x">* then, with a tool like PhotoShop or the GIMP, create a new</span> </span><span id="L-32"><a name="L-32"></a><span class="x">* layer filled with that color, then invert it and set the</span> </span><span id="L-33"><a name="L-33"></a><span class="x">* blend mode to &quot;Overlay&quot;.</span> </span><span id="L-34"><a name="L-34"></a><span class="x">*************/</span> </span></pre></div> </td></tr></table>
color, colors, dominant, image, php, rgb