hack-a-barcode

HACK A SOFTSTRIP BARCODE.

MarkO(lerholser) posted the image `marko-barcode-to-decode.jpg` and
asked if software existed to decode it.

In GIMP, I rotated it, scaled it 10x with cubic interpolation,
and used threshold to make it black&white.  I saved that as
`marko-barcode-to-decode-threshold.png`.

Then I wrote `hack.go` to decode the image.  First I figure out
(with some trial & error & measuring) starting points and strides
in X and Y directions to pick points to decode.  That is output as
`out.chosen_points.png`.

I did my own exploration and figured out
the dibit format.  Then I used info from a blog post
https://www.insentricity.com/a.cl/265/encoding-software-in-barcodes-the-eight-bit-magazine-way
to extract two bytes and parity bits from each line.  I'm guessing that
the bytes are output like I did, but bits could be reversed or something.

I don't recognize the output format in `out.bin`, so I have no idea what
it is.  `out.hex` shows the same thing, in hex, and with the headers.
The payload begins after the three 00's on the second line.  And `out.txt`
shows my work.

THERE IS CORRUPTION about a third of the way down, where there are
strings of 00 bytes.  That's because my points don't line up correctly
in that part of the image.  I have yet to fix that.