这段代码可以帮助你判断任意图片的主色调，使用了简单的统计算法实现

$i = imagecreatefromjpeg("image.jpg");        for ($x=0;$x<imagesx($i);$x++) {       for ($y=0;$y<imagesy($i);$y++) {           $rgb = imagecolorat($i,$x,$y);           $r   = ($rgb >> 16) & 0xFF;           $g   = ($rgb >>  & 0xFF;           $b   = $rgb & 0xFF;                $rTotal += $r;           $gTotal += $g;           $bTotal += $b;           $total++;       }   }        $rAverage = round($rTotal/$total);   $gAverage = round($gTotal/$total);   $bAverage = round($bTotal/$total);