ASM Blocking Image Uploads

The best way to do this is with multipart content type. There exist different subtypes, i.e. related or mixed. In my opinion, it is the best way to transport files. Here, you don't need base64. The file can be apend at the rest request without convert it before.

You can look here http://stackoverflow.com/questions/4083702/posting-a-file-and-data-to-restful-webservice-as-json

or http://www.w3.org/Protocols/rfc1341/7_2_Multipart.html