Thursday, December 17, 2015

on facewatch

pavel_lishin 2 hours ago

I wonder if the CV Dazzle[1] style will take off in the UK. Maybe we'll finally get the exact cyberpunk future promised us by Gibson, etc.
[1] reply

bsenftner 2 hours ago

No need to go that far: every system I'm aware of fails when there are no eyebrows. (I'm in the FR industry.)


fredley 2 hours ago

This does not scale. It might work for a few people in a population of thousands, but beyond that false positives are going to be a real problem.

bsenftner 2 hours ago

I work in facial recognition. When you say it does not scale, how so? I have a system with 975K people in it, the US registered sex offenders database, and with a single quad core laptop a lookup takes about 8 seconds. With a server class 32+ core system the lookup is nearly real time. How does that not scale?

ensignavenger 2 hours ago

I think the OP was concerned about false positives, not processing times. If you ran, say, 10,000 faces through your system/day for a year, how many false positives would you get?

ultramancool 2 hours ago

I assume he more meant accuracy at scale - if you have a large population how does the accuracy do? Do you wind up with many close samples or are things pretty good?

bsenftner 2 hours ago

Pretty much all FR systems generate a list of matches, ranked from closest match on down. The size of the list is configurable. It is also industry standard NOT to use the list as an authority. Given a list of high matches (greater than 90%) a human can quickly filter out obvious false positives, and then the remaining are retained for further consideration. It is also industry standard NOT to rely on FR alone; combining FR with other measures reduces the ability for a false positive.
The issue I find with FR is people expecting it to be some super technology, gleaming significant information from a dust spec. Its not like that. And the media is playing it up with unrealistic descriptions. Remember the original DOOM and it's quality of graphics? That is where FR is now. We've got a ways before the journalist hype is close to reality. And the mature technology will not be FR, but a comprehensive multiple biometric measuring system capturing far more than someone's face.

Retric 1 hour ago

So, if you’re looking for 1% of a total population your false positive rate before human intervention is 99%. That's not useful for automated systems.
Further, identical twins are going to show an image that would fool human verification making this questionable for many tasks even with human supervision.
PS: Almost 1% of the population has an identical twin. (% of births is lower, but you get 2 twins.)

bsenftner 1 hour ago

There is only one true match. So the system will always be generating false positives. This technology is not an authority, but a filter. Yes, identical twins will both be identified if they are both in the system and no additional biometric measures are included. Identical twins still have different retina, and due to lifestyles identical twins beyond age 30 can be distinguished apart fairly easily.

from lizard's ghost

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