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To: metmom; I want the USA back
I did a quick calculation to see how reasonable this idea is, and was surprised by the result.

The resolution of the iPhone 7's wide-angle camera is approximately 4600x2600 pixels with a field-of-view of about 63 degrees width; this translates to an angular resolution of about 240 microradians per pixel.

It's surprisingly difficult to find hard numbers giving the distance between fingerprint ridges and grooves, but I was able to come up with a estimate of 0.05 mm (50 microns) for the closest spacing after some looking.

At one meter distance, this is 50000 microradians per pixel, which means that at distance of one meter, the iPhone wide-angle camera can put almost 210 pixels on each pair of ridges!

This makes the article's claim believable, although getting enough contrast on a fingertip to pick up individual ridges and grooves is questionable; with optical contrast only (no ink or surface-contact effects) a great deal of dynamic range would be required to obtain a fingerprint of sufficient quality to do personal identification.

Still, it's only a matter of time before this is possible.

33 posted on 01/22/2017 7:03:55 AM PST by Steely Tom (Liberals think in propaganda)
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To: Steely Tom

If they can get a crystal clear picture of finger prints then why the heck can’t they get half decent not so blurry youtubes?

Today it’s finger prints and facial recognition, tomorrow it’s irises. Might as well submit to burkas.


40 posted on 01/22/2017 8:02:50 AM PST by bgill (From the CDC site, "We don't know how people are infected with Ebola")
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