OCR图片文字识别问题 ，简单的单个汉字怎么也识别不了？

简单的单个汉字怎么也识别不了？

图片地址： http://pic.baike.soso.com/p/20140416/20140416005107-2127270878.jpg

{"code":"Success","imageResults":[{"errorResult":{},"illegalResult":{},"imageName":"http://pic.baike.soso.com/p/20140416/20140416005107-2127270878.jpg","ocrResult":{"text":[]},"pornResult":{},"qrcodeResult":{"qrcodeList":[]},"spamResult":{"keywordResults":[]},"taskId":"9ecb356a-89e9-46ae-95e0-1a3e1fd59bf3-1473481911438"}],"msg":"调用成功。"}