PHP GD压缩图片

public function zip_pic(){
ini_set("memory_limit","256M"); //修改php分配的内存
$filename = './images/imgp0627.jpg';
$percent = 1;

// 内容类型
header('Content-Type: image/jpeg');

// 获取新的尺寸

list($width, $height) = getimagesize($filename);
$new_width = $width ;//* $percent;
$new_height = $height ;//* $percent;

// 重新取样
$image_p = imagecreatetruecolor($new_width, $new_height);
$image = imagecreatefromjpeg($filename);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);

// 输出
imagejpeg($image_p, './images/imgp0627-2.jpg', 70);

}