We sort of use IA's data already, because many Wikisource texts are
OCR'ed on IA. If we manage to use OCR improvements within DjVu, it
shouldn't be too difficult to reupload such DjVu in their items and then
they could do what they want with them.
OCRs generally work by finding lines of text on a
page, splitting the
lines
into letters, then recognizing each letter separately. So, an OCR would
know,
for each letter of the recognized text, what is its bounding box on
the page.
However, to my knowledge there is not a single OCR that exports this
data, nor
is there a standard format for it. If an open source
OCR could be
modified to
do this, then it would be easy to inject data
retreieved from
captchas back
into OCR-ed text. And it could be used for so much
more :)
I don't understand, what data are you talking about? DjVu is an open
format and can store character mappings, which is what the wikicaptcha
proof of concept is based on. There's also
https://en.wikipedia.org/wiki/HOCR and IA uses some proprietary ABBYY
xml format which AFAIK can be somehow read and converted to hOCR.
The real problem is character training which could be used for
subsequent OCRs. I doubt we can do much here, because everyone uses
ABBYY, and even tesseract users don't seem to share such data in any way.
Nemo