Storing Images In DB Using Django Models
I think the best approach is to store the 'main file' in your media path of your project and save the address of file(path to the file) in your model. this way you dont need to convert....
I am using Django for creating one Web service and I want that web service to return Images. I am deciding the basic architecture of my Web service. What I came up to conclusion after stumbling on google is:

I should store Images in DB after encoding them to Base64 format.
Transferring the Images would be easy when directly Bases64 decoded string is transmitted.

But I have one issue how can I  store bases64 encoded string in DB using Django models? Also, if you see any flaw in my basic architecture please guide me. 
I am new to Web services and Django
Thanks!!