H. Xie

@ #293 In my case. The mentioned error is caused by the way `jsmpeg` create websocket. It create with an subprotocol called 'null', which means server should accept the connection...

当载入checkpoint失败时，infer得到的图像底色会很奇怪（我不认识那个颜色） 注意！infer未能载入checkpoint的时候不会中断，只会输出一行提示 ```fail to restore model XXXX/checkpoint``` 在训练时，程序保存checkpoint的路径会更深，打开`XXXX/checkpoint` 文件夹，infer前需要看一下。 当正确载入模型时，提示 ```restored model XXXX/checkpoint/experiment_0_batch_16``` 可以得到预期的图像**白底黑字**