[nzlug] computer read/write access to paper?

[Karl.]

Thanks to everyone who gave responses to my question.  After a bit of
digging I haven't found anything which is directly usable enough that I
have time to pursue it at the moment (and it was never important
anyway).  Here's a summary of what I encountered.


On Fri, Jun 22, 2007 at 10:32:07AM +1200, Toby Collett wrote:
> Have a look at artoolkitplus
> http://studierstube.icg.tu-graz.ac.at/handheld_ar/artoolkitplus.php
> They have a set of 2d tags that can be recognised with low quality web cams

There's a lot of interesting info there - thanks for the link  :-)

 
On Fri, Jun 22, 2007 at 10:34:19AM +1200, Stephen Judd wrote:
> Paper? How boring. Why not a secret decoder ring? 

The secret decoder ring is the next step, obviously - I just needed to
lay the groundwork first.

> >Vague thoughts:  I could hack up my own method by choosing a subset of
> >characters which are consistently well recognized by ordinary OCR
> >software.  eg.  don't use Q because it looks too much like O, etc.
> 
> You know, 1 and 0 are very distinguishable. I suggest binary.

"1" and "0" are pretty good, but even better, I think, is what they use
for dataglyphs: "/" & "\"
http://www.parc.com/research/projects/dataglyphs/default.html

They also allow printing the characters with varying weights (boldness)
so that you can have your 'barcode' look like a greyscale image (look at
the link to see examples).


On Mon, Jun 25, 2007 at 08:30:17AM +1200, Guy K. Kloss wrote:
> May want to check QRcode, a Japanese standard that's becoming quite popular, 
> and many cell phones have got built in decoders. Handles poor image quality 
> apparently quite well, and you can do all kinds of stuff with it. You can 
> read up on it using Wikipedia ...

QRcode looks to have great potential.  I found some decoders for it, but
not in a language I was comfortable in.  Was very tempted to try writing
my own (in Python, probably), but managed to resist - I have enough
'unimportant' projects sucking up my time anyway  :-)   It would be
great if QRcode manages to spread beyond Japan.

PDF417 also looked good, but I lost interest/time before pursuing it.
http://www.barcodeman.com/faq/2d.php
 

On Mon, Jun 25, 2007 at 08:39:49AM +1200, Michael Field wrote:
> 
> > Vague thoughts:  I could hack up my own method by choosing a subset of
> > characters which are consistently well recognized by ordinary OCR
> > software. 
> >
> > Karl.
> 
> Now that is a simple to test...
> 
> I've got a program that I wrote to allow me to suck binary files down a
> dial-up terminal connection (without X/Y/Z modem), which I slightly
> modified. You could use that, but just customize the alphabet. My goal
> was a small encoder that I could cut-and-paste it to the remote system
> and compile there, or write the equivalent in any other handy language. 

Thanks for the programs.  My original thought was to wonder if it was
possible to mash up something in bash (which is sufficiently ubiquitous,
as far as I am concerned) - I wondered if there were any existing
command-line tools to do Reed-Solomon encoding and stuff like that (you
never know what wacky command-line tools you will find until you start
looking).  

For the moment it has all returned to the back-burner for another few years.


Karl.