This whole discussion reminds me of work we did in the early 80's trying to convert typesetting tapes into TeX/Metafont for display/printing. One the things we

This whole discussion reminds me of work we did in the early 80's trying to convert typesetting tapes into TeX/Metafont for display/printing. One the things we tried was converting scanned images into rectangles which could then be typeset by TeX using 'rules' of various sizes. Another approach was to convert the scans into specialized fonts, either whole or in contiguous chunks that could be assembled.