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This story is really alarming because as described, the police ran a face recognition tool based on a frame of grainy security footage and got a positive hit. D

• Pxtl 6y ago
  Intresting and related, a team made a neat "face depixelizer" that takes a pixelated image and uses machine learning to generate a face that should match the pixelated image. What's hilarious is that it makes faces that look nothing like the original high-resolution images. https://twitter.com/Chicken3gg/status/1274314622447820801 https://twitter.com/Chicken3gg/status/1274314622447820801
  • mywittyname 6y ago
    I wonder if this is trained on the same, or similar, datasets.
    • jcims 6y ago
      One of the underlying models, PULSE, was trained on CelebAHQ, which is likely what the results are mostly white-looking. StyleGAN, which was trained on the much more diverse (but sparse) FFHQ dataset does come up with a much more diverse set of faces[1]...but PULSE couldn't get them to converge very closely on the pixelated subjects...so they went with CelebA [2]. [1] https://github.com/NVlabs/stylegan https://github.com/NVlabs/stylegan [2] https://arxiv.org/pdf/2003.03808.pdf https://arxiv.org/pdf/2003.03808.pdf (ctrl+f ffhq)
  • jacquesm 6y ago
    That should be called a face generator, not a depixelizer.
    • Polylactic_acid 6y ago
      Basically. The faces look plausible but less useful than the original blurred image.
  • danso 6y ago
    What's sad is that a tech entrepreneur will definitely add that feature and sell it to law enforcement agencies that believe in CSI magic: https://www.youtube.com/watch?v=Vxq9yj2pVWk https://www.youtube.com/watch?v=Vxq9yj2pVWk
    • barrkel 6y ago
      And another entrepreneur can add a feature to generate 10 different faces which match the same pixelation, and sell it to the defence.
      • emiliobumachar 6y ago
        A better strategy might be to pixelate a photo of each member of the jury, than de-pixelate it through the same service, and distribute the before and after. Maybe include the judge and prosecutor.
      • heavyset_go 6y ago
        Doubt that many people can afford to hire an expert witness, or hire someone to develop bespoke software for their trial.
  • nfrmatk 6y ago
    Interesting... Neat... Hilarious... In light of the submission and the comment you're responding to, these are not the words I would choose. I think there's genuine cause for concern here, especially if technologies like these are candidates for inclusion in any real law enforcement decision-making.
  • 2038AD 6y ago
    Ironically, if the police had used and followed the face depixelizer then we may not have had the false arrest of a black man - not because of accuracy but because it doesn't produce many black faces
• caconym_ 6y ago
  People are not good at understanding uncertainty and its implications, even if you put it front and center. I used to work in renewable energy consulting and I was shocked by how aggressively uncertainty estimates are ignored by those whose goals they threaten. In this case, it's incumbent on the software vendors to ensure that less-than-certain results aren't even shown to the user. American police can't generally be trusted to understand nuance and/or do the right thing.
• adim86 6y ago
  I blame TV shows like CSI and all the other crap out there that make pixelated images look like something you could "Zoom" into or something the computer can still understand even if the eye does not. Because of this, non tech people do not really understand that pixelated images have LOST information. Add that to the racial situation in the U.S. and the the inaccuracy of the tool for black people. Wow, this can lead to some really troublesome results
  • ficklepickle 6y ago
    I lose hours every day just yelling "enhance" at my computer screen. Hasn't worked yet, but any day now...
    • auggierose 6y ago
      Bladerunner
• zaroth 6y ago
  > Does this tool give any indication of a confidence value? Yes. > Does it return a list (sorted by confidence) of possible suspects, Yes. > ... or any other kind of feedback that would indicate even to a layperson how much uncertainty there is? Yes it does. It also states in large print heading “THIS DOCUMENT IS NOT A POSITIVE IDENTIFICATION IT IS AN INVESTIGATIVE LEAD AND IS NOT PROBABLE CAUSE TO ARREST”. You can see a picture of this in the ACLU article. The police bungled this badly by setting up a fake photo lineup with the loss prevention clerk who submitted the report (who had only ever seen the same footage they had). However, tools that are rife for misuse do not get a pass because they include a bold disclaimer. If the tool/process can not prevent misuse, the tool/process is broken and possibly dangerous. That said, we have little data on how often the tool results in catching dangerous criminals versus how often it misidentifies innocent people. We have little data on if those innocent people tend to skew toward a particular demographic. But I have a fair suspicion that dragnet techniques like this unfortunately can be both effective and also problematic.
  • danso 6y ago
    I think the software would be potentially less problematic if the victim/witness were given access, and (ostensibly) could see the pool of matches and how much/little the top likely match differed from the less confident matches. > The police bungled this badly by setting up a fake photo lineup...* FWIW, this process is similar to traditional police lineups. The witness is shown 4-6 people – one who is the actual suspect, and several that vaguely match a description of the suspect. When I was asked to identify a suspect in my robbery, the lineup included an assistant attorney who would later end up prosecuting the case. The police had to go out and find tall slight-skinned men to round out the lineup. > ... with the loss prevention clerk who submitted the report (who had only ever seen the same footage they had). Yeah, I would hope that this is not standard process. The lineup process is already imperfect and flawed as it is even with a witness who at least saw the crime first-hand.
• strgcmc 6y ago
  I think the NYT article has a little more detail: https://www.nytimes.com/2020/06/24/technology/facial-recognition-arrest.html https://www.nytimes.com/2020/06/24/technology/facial-recogni... Essentially, an employee of the facial recognition provider forwarded an "investigative lead" for the match they generated (which does have a score associated with it on the provider's side, but it's not clear if the score is clearly communicated to detectives as well), and the detectives then put the photo of this man into a "6 pack" photo line-up, from which a store employee then identified that man as being the suspect. Everyone involved will probably point fingers at each other, because the provider for example put large heading on their communication that, "this is not probable cause for an arrest, this is only an investigative lead, etc.", while the detectives will say well we got a hit from a line-up, blame the witness, and the witness would probably say well the detectives showed me a line-up and he seemed like the right guy (or maybe as is often the case with line-ups, the detectives can exert a huge amount of bias/influence over witnesses). EDIT: Just to be clear, none of this is to say that the process worked well or that I condone this. I think the data, the technology, the processes, and the level of understanding on the side of the police are all insufficient, and I do not support how this played out, but I think it is easy enough to provide at least some pseudo-justification at each step along the way.
  • danso 6y ago
    That's interesting. In many ways, it's similar to the "traditional" process I went through when reporting a robbery to the NYPD 5+ years ago: they had software where they could search for mugshots of all previously convicted felons living in a x-mile radius of the crime scene, filtered by the physical characteristics I described. Whether the actual suspect's face was found by the software, it was ultimately too slow and clunky to paginate through hundreds of results. Presumably, the facial recognition software would provide an additional filter/sort. But at least in my situation, I could actually see how big the total pool of potential matches and thus have a sense of uncertainty about false positives, even if I were completely ignorant about the impact of false negatives (i.e. what if my suspect didn't live within x-miles of the scene, or wasn't a known/convicted felon?) So the caution re: face recognition software is how it may non-transparently add confidence to this already very imperfect filtering process. (in my case, the suspect was eventually found because he had committed a number of robberies, including being clearly caught on camera, and in an area/pattern that was easy to narrow down where he operated)
• throwaway894345 6y ago
  > But the other side of it is: would police be more hesitant to act on such fuzzy evidence if the top match appeared to be a middle-class Caucasian (i.e. someone who is more likely to take legal recourse)? Honest question: does race predict legal recourse when decoupled from socioeconomic status, or is this an assumption?
  • advisedwang 6y ago
    Race and socioeconomic status are deeply intertwined. Or to be more blunt - US society has kept black people poorer. To treat them as independent variables is to ignore the whole history of race in the US.
    • throwaway894345 6y ago
      > To treat them as independent variables is to ignore the whole history of race in the US. Presumably the coupling of the variables is not binary (dependent or independent) but variable (degrees of coupling). Presumably these variables were more tightly coupled in the past than in the present. Presumably it's useful to understand precisely how coupled these variables are today because it would drive our approach to addressing these disparities. E.g., if the variables are loosely coupled then bias-reducing programs would have a marginal impact on the disparities and the better investment would be social welfare programs (and the inverse is true if the variables are tightly coupled).
  • SkyBelow 6y ago
    >Honest question: does race predict legal recourse when decoupled from socioeconomic status, or is this an assumption? I think the issue is that regardless of the answer, it isn't decoupled in real world scenarios. I think the solution isn't dependent upon race either. It is to ensure everyone have access to legal recourse regardless of socioeconomic status. This would have the side effect of benefiting races correlated with lower socioeconomic status more.
    • throwaway894345 6y ago
• bsenftner 6y ago
  > The issue of face recognition algorithms performing worse on dark faces is a major problem. This needs to be coupled with the truth that people (police) without diverse racial exposure are terrible at identifying people outside of their ethnicity. In the photo/text article they show the top of the "Investigative Lead Report" as an image. You mean to say that every cop who saw the two images side by side did not stop and say "hey, these are not the same person!" They did not, and that's because their own brains' could not see the difference. This is a major reason police forces need to be ethnically diverse. Just that enables those members of the force who never grew up or spent time outside their ethnicity can learn to tell a diverse range of similar but different people outside their ethnicity apart.
• peroporque 6y ago
  It wouldn't make it into the newspapers, so it doesn't matter.