The first question is, what does 'accessing images' mean? Reading the data, to display on a page? Adding, removing, deleting? Also, what scope do you want to access the images in? If it's from the client/designer, there are a lot more hurdles than on the gateway.
This thread has some useful information:
Oh, and let me say up front this time - doing anything where you have to interact with the API will not be supported by support. That's not to say that it's actually bad, but careless use of internal methods could lead to unintended consequences.