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PHP生成同比例的缩略图代码

分类:PHP   来源:网络   时间:2011-03-12 20:24:30

创建图像缩略图需要许多时间,此代码将有助于了解缩略图的逻辑。
 
/**********************
*@filename - path to the image
*@tmpname - temporary path to thumbnail
*@xmax - max width
*@ymax - max height
*/
function resize_image($filename, $tmpname, $xmax, $ymax)
{
    $ext = explode(".", $filename);
    $ext = $ext[count($ext)-1];

    if($ext == "jpg" || $ext == "jpeg")
        $im = imagecreatefromjpeg($tmpname);
    elseif($ext == "png")
        $im = imagecreatefrompng($tmpname);
    elseif($ext == "gif")
        $im = imagecreatefromgif($tmpname);

    $x = imagesx($im);
    $y = imagesy($im);

    if($x <= $xmax && $y <= $ymax)
        return $im;

    if($x >= $y) {
        $newx = $xmax;
        $newy = $newx * $y / $x;
    }
    else {
        $newy = $ymax;
        $newx = $x / $y * $newy;
    }

    $im2 = imagecreatetruecolor($newx, $newy);
    imagecopyresized($im2, $im, 0, 0, 0, 0, floor($newx), floor($newy), $x, $y);
    return $im2;
}

 

文章来源:侠客站长站(www.xkzzz.com) 详文参考:http://www.xkzzz.com/zz/netbc/php/201009/22-56337.html

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