I need to read an image and save it but failed with strange issue. 

The first step is to load with $.ajax and seems very simple.

2. $.ajax({
3.   url : "http://www.izhaiyiqi.com/ce/tbtfscom/tbcaps/s.gif",
4.   success: function(){
5.   // second is to save it
6.   }
7. });

s.gif is a one dot image. And I can see strings like "GIF89a

����!�
,

D
;". I thought it's the valid gif data and tried to transfer the data with $.ajax. But this is the second question. 

The first thing I cannot explain is, if I visit " http://www.izhaiyiqi.com/ce/tbtfscom/tbcaps/s.gif" directly, it returns "R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==" which seems to be something Base64 encoded. Why isn't it a valid image bytes array? I pretty sure that the image is OK.

Below is the  snapshot of  request header from Chrome. 

Would be deeply appreciated if anybody helps.