Make raw depth array more efficient

[shiffman]

I'm rewriting the data as an array of ints, i can leave it as a ShortBuffer or just use the array() function to convert

[guyjbrown]

Daniel, thanks so much for this excellent work. It would be useful to be able to get the depth image in its most raw form - a block of bytes or shorts. I'm interested in using the depth image as the basis for video frames, so need to be able to write the data to disk efficiently and compactly.