用 php 压缩图片

如何用php  压缩图片 废话不说 直接上代码

header("Content-type: image/jpeg");
//获取图片路径
$file = "123.jpg";

$percent = 0.3; //图片压缩比

list($width, $height) = getimagesize($file); //获取原图尺寸

//缩放尺寸

$newwidth = $width * $percent;


$newheight = $height * $percent;

$src_im = imagecreatefromjpeg($file);

$dst_im = imagecreatetruecolor($newwidth, $newheight);

imagecopyresized($dst_im, $src_im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);

imagejpeg($dst_im,$file); //输出压缩后的图片

imagedestroy($dst_im);

imagedestroy($src_im);