Interesting People mailing list archives
Re: face recognition flop why do I not believe this
From: David Farber <dave () farber net>
Date: Thu, 26 Jul 2007 16:21:39 -0400
Begin forwarded message: From: Jeff Jonas <jeffjonas () us ibm com> Date: July 26, 2007 1:54:14 PM EDT To: dave () farber net Subject: Re: [IP] Re: face recognition flop why do I not believe thisRe: the comment on this thread -- "The only place I'm aware of facial recognition technology has met a measure of success has been in casinos, where the indoor controlled environment, the large number of cameras, basically stationary people and large security forces has resulted in usable results."
This is untrue. The only use case in the gaming industry I know of where facial recognition produces any useful results at all is when a surveillance room operator is already observing one specific person (because of some other trip-wire). When observing the person the surveillance room operator wonders if this face is in one of their mug books (e.g., The Griffin Book). Facial recognition enables them to take this person of interest and rank the mug book(s) into most likely look-a-likes.
I deployed the first such system that did this in the gaming industry back in 1996. Facial recognition is only marginally useful in this setting ... even when the subject of interest is preselected. And the bigger the mug book (watch list) the less useful facial recognition becomes.
So the notion of crowd scanning for bad guys in Vegas is entirely theatre.
Jeff Jonas Distinguished Engineer and Chief Scientist IBM Entity Analytics 702.851.4697 JeffJonas () us ibm com My blog: www.jeffjonas.typepad.com
David Farber <dave () farber net> David Farber <dave () farber net> 07/26/2007 09:49 AM Please respond to dave () farber net
To
ip () v2 listbox com
cc
Subject
[IP] Re: face recognition flop why do I not believe this
Begin forwarded message: From: Tom Goltz <tgoltz () quietsoftware com> Date: July 26, 2007 11:13:39 AM EDT To: dave () farber net Cc: Brian Randell <Brian.Randell () ncl ac uk> Subject: Re: [IP] face recognition flop why do I not believe this At 08:20 PM 7/25/2007, you wrote: > While the media got it wrong including the BKA's own president Jörg > Ziercke - from a scientific perspective - these tests were a success > With minimal human interference - false positive ratio was kept > quite small - 0.1 percent I don't believe it either. Let's do the numbers. If you have a stadium that holds 50,000 people, and you screen all of them with this technology, at a false- positive rate of 0.1%, you'll get 50 false positives. Assuming that you detain all 50 for further investigation, and some significant percentage of those people are members of parties who choose to remain with the detained person, you'll be detaining and handling between 100 and 200 people, most of whom will NOT be happy about the situation they find themselves in. The article goes on to suggest that the solution to this high false- positive rate is to have a human double-check the match before sounding the alarm. The catch with this is that unless you're going to design a fairly long gauntlet to run everyone through single-file, you won't have TIME for a person to confirm the match before the subject is lost in the crowd, unless you detain the suspect person ("sound the alarm"). What also is not mentioned is the false-negative rate associated with this test. In all of the realistic field tests I have seen to date of face-recognition technology, the only way they've managed to get the false-positive rate down to one-tenth of one percent was to set the match requirements so tight that the false-negative rate skyrocketed to such high levels that the system became essentially useless. The article claimed that both the false-negative and false- positive rates were at 0.1%, but neglected to mention if both were held to that low rate at the same time with the same settings. Sporting events and mass-transit stations are particularly problematic for computerized facial recognition technology, as depending on the season you'll need to get your subjects to cooperatively remove their hats, scarves, and sunglasses and all look into the camera under consistent lighting conditions. The only place I'm aware of facial recognition technology has met a measure of success has been in casinos, where the indoor controlled environment, the large number of cameras, basically stationary people and large security forces has resulted in usable results. ------------------------------------------- Archives: http://v2.listbox.com/member/archive/247/=now RSS Feed: http://v2.listbox.com/member/archive/rss/247/ Powered by Listbox: http://www.listbox.com ------------------------------------------- Archives: http://v2.listbox.com/member/archive/247/=now RSS Feed: http://v2.listbox.com/member/archive/rss/247/ Powered by Listbox: http://www.listbox.com
Current thread:
- Re: face recognition flop why do I not believe this David Farber (Jul 26)
- <Possible follow-ups>
- Re: face recognition flop why do I not believe this David Farber (Jul 26)
- face recognition flop why do I not believe this David Farber (Jul 26)
- Re: face recognition flop why do I not believe this David Farber (Jul 26)
- Re: face recognition flop why do I not believe this David Farber (Jul 27)
- Re: face recognition flop why do I not believe this David Farber (Jul 28)