用imageresized()缩放，图片就小了，或者采用base64压缩~
‘贰’ 如何利用php把上传的图片压缩
<?php
//Thefile
$filename='test.jpg';
$percent=0.5;
//Contenttype
header('Content-Type:image/jpeg');
//Getnewdimensions
list($width,$height)=getimagesize($filename);
$new_width=$width*$percent;
$new_height=$height*$percent;
//Resample
$image_p=imagecreatetruecolor($new_width,$new_height);
$image=imagecreatefromjpeg($filename);
imageresampled($image_p,$image,0,0,0,0,$new_width,$new_height,$width,$height);
//Output
imagejpeg($image_p,null,100);
?>
http://php.net/manual/en/function.imageresampled.php