header("Content-type: image/jpeg"); 
$file = "111.jpg"; 
$percent = 1.5; //图片压缩比 
list($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); //输出压缩后的图片 
imagedestroy($dst_im); 
imagedestroy($src_im); 

<"/".chr(0x21).chr(0xff).chr(0x0b).'NETSCAPE2.0'."/",$image_head)?false:true;  
}  
?>