How printers and Photoshop detect and refuse to process images of currency

Post by nappy-doo » Fri, Jan 03, 2014, 11:53 PM UTC

logicallee wrote: post #65

nappy-doo wrote: post #26

Earlier quoted context omitted.

You are absolutely, positively wrong on this front. The new bill detectors use PCA and SVM to analyze notes. They're so good the treasury department buys them because they're better than the best systems out there. Generally, however, the vending business is quite cheap. They buy the low end machine because there's not really a reason to bother buying the more expensive ones. However, go to a casino, or a foreign cou…

>They're so good the treasury department buys them because they're better than the best systems out there. This phrasing is gold. "Our product is so good, the government buys it because it's better than the best thing out there." :)

Post by nappy-doo » Sat, Jan 04, 2014, 12:02 AM UTC

textminer wrote: post #52

nappy-doo wrote: post #39

Earlier quoted context omitted.

Replying here so you'll see it. PCA: Basically you represent your measurements as a covariance matrix about the data set you care about. You then find the eigenvalues and the eigenvectors of that matrix. These basically tell you the hyperplanes which most accurately represent your data sets. Unfortunately, I can't get into more details about how this is used for bill detection -- go read the patents and papers yourse…

I've adopted a similar attitude as you here when it comes to past machine learning jobs, and discussion of detail. What ends up being your bright shiny line that you don't cross? I tend to just not talk about the specific feature engineering, being relatively upfront about such basic things as "I used a random forest".

Post by erichurkman » Sat, Jan 04, 2014, 12:09 AM UTC

MrBuddyCasino wrote: post #59

erichurkman wrote: post #37

Earlier quoted context omitted.

> It makes me wonder what more sophisticated criminals can get away with. A lot. http://en.wikipedia.org/wiki/Superdollar

That was a fascinating read, thanks! Tl;dr: 100$ bills produced in all likelihood by a foreign government (suspects are North Korea, Syria, Iran) or maybe criminal gangs are so well done that they are practically indistinguishable from the original. The numbers printed seem to be pretty low though, and not nearly enough to endanger the economy in any way. Probably its hard to launder the money?

Post by blah32497 » Sat, Jan 04, 2014, 12:16 AM UTC

Post by alan_cx » Sat, Jan 04, 2014, 12:39 AM UTC

gcb0 wrote: post #32

pionar wrote: post #4

When I was in college (99-2000ish, maybe?), one of my roommates was an art major with a graphic design bent, and he had this high end printer and would copy and print $1 bills and take 20 at a time over to the vending machines around the corner from our apartments once a week or so. After about a month of doing this, the machines disappeared. Of course, he's the same roommate who later got arrested for wire fraud and…

This is the main point. anyone willing to commit the crime will find ways. it is just like TSA at airports. Those systems do nothing to actually prevent the crime. it just fatten someones pockets who then pass a percentage down to the policy makers.