base64_img_php
用于base64图像编码和解码PHP类
##用法
require 'path/to/class/b64img.php' ;
// encode file as data uri
$ image1 = new B64img ( './some_image.png' );
$ data_URI = $ image1 -> get_data ();
// save data uri as file
$ image2 = new B64img ( $ data_URI );
$ image2 -> save_as ( './new_image.png' );