Umm, we're talking about just over 18MB here (1200 * 1000 pixels, 16 bytes/pixel, see http://pixenomics.tumblr.com/post/16895861678/how-to-send-1-...). That you can just dump over the wire as a binary blob. Why are we talking about this again? Use your favourite language, just keep it in a big blob in memory, and have fun.
Memory isn't an issue. It's processing the data and turning the storage into a format the client can read. A big blob isn't easy to send to the client unless it's an image or something and then it becomes an issue when you want to manipulate the data or process it.