Subj : Re: writing a software barcode reader
To   : comp.programming
From : Thad Smith
Date : Thu Oct 06 2005 04:53 pm

Eric.Medlin@gmail.com wrote:
> 
> Thad Smith wrote:
> >
> > I would assume round-off errors associated with scaling.
> 
> That might be true but the specs I have on barcodes tell you when to
> round down and round up when scaling so you don't have half pixels.  So
> I wasn't sure if that was it or not.  I would just be happier if my
> numbers matched exactly.

I expect that the sample was not produced according to your spec,
assuming you are reading the spec correctly.  It probably works OK due
to the sloppiness allowed, but not strictly conforming.  You might
have your program also display deviance from the spec.  In that case,
you would probably be computing a "best fit" response to scale and
other parameters.

Thad

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