Re: Security markings on the ballot

From: Douglas W. Jones <jones_at_cs_dot_uiowa_dot_edu>
Date: Sun Oct 26 2003 - 19:32:09 CST

On Sunday, October 26, 2003, at 03:10 PM, David Mertz wrote:

> I'm warming up more to the value of watermarks with adjustable
> placement. Part of the problem to my mind is that you cannot really
> count on a printer feeding entirely accurately.

right.

> However, the RELATIVE position of various things on the page is much
> more consistent. There might still be a rare partial misfeed, but
> generally the page image is accurate within its margins.

Right again. I recently saw a truly stunning Fax where the original
must have jammed on one side and slowly rotated past the image sensor
while the received copy printed normally. The resulting distortion of
the text reminded me of something by MC Escher.

> As far as I can see, two images would only allow one completely reliable
> dimension of variable placement--i.e. the distance between them.

You're forgetting the fixed landmarks on the page -- election time and
date, county name, barcode and all that. Those landmarks stay put, so
it is the relationship of the movable elements to that material that
will be the most obvious. These fixed landmarks are printed in black,
not just ghost background images, so they'll be the things your eye
latches onto, probably more strongly than you latch onto the edges
of the paper.

                                Doug Jones
                                jones@cs.uiowa.edu
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Received on Fri Oct 31 23:17:04 2003

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