What I don't get is why the emphasis on sheet music as an image? I get that mapping from an auditory stream onto a score is an interesting problem, but isn't i

What I don't get is why the emphasis on sheet music as an image? I get that mapping from an auditory stream onto a score is an interesting problem, but isn't it naturally decoupled from the visual processing problem of reading and segmenting images of sheet music? Wouldn't it make more sense to deal primarily with a digital intermediate encoding of the score? What am I missing?