Couldn't you upload the file to a blob, keeping it client side?
Re:
MarcellusDrum
lol, so much so, I create games in javascript so I only need a static server.
The script do run on the client side, but it can't access images from your computer, so you will have to upload it first so it can access it from the server.
It may be possible via the FileReader API
Yeah, but you don't upload it - you just make it accessible to the browser. So you read it into memory, but you would do the same with a "native" program (despite the fact that a very large file might be read more intelligently if it doesn't fit into RAM).