Would there be a way to add a shorthand stylus or photo recognition system?

Shorthand can write at about 80 to 150 wpm and is based on a phonetic style of terms.

It is used in India and by many reporters.

While niche, with the prevalence of Ipads and Microsoft Surface and Samsung Note, it seems like a way to add up to 200wpm input.

Pitman and other shorthand handwriting systems are used in India, Nigeria and by Journalists, some medical and Administrators.

It is fairly rare but its possible to hand write at around 70 to 200wpm which is as fast as any normal person speaks.

How hard would it be to teach a visual processor to read in the text?

It does skip vowels, it can have some words identified by context (PL could be App, Apple or Apply) and text can generally be somewhat messy, but as a problem set it seems not much more difficult than recognising English handwriting or Arabic.