9 ms·

Anyone would be supportive of judges being cautious over upscaling, which we know has the potential to introduce false information because it's doing inference

• ImprobableTruth 5y ago
  How do you think zooming works?
  • Twisol 5y ago
    If the pre-zoomed image was already downscaled (e.g. to fit a small display), then up to a point, zooming should simply downscale less, i.e. remove fewer pixels. Beyond that point, yes, a zoom would have to perform some kind of interpolation. In the CSI "zoom and enhance", anything beyond the simplest forms of interpolation would be part of "enhance", which is to say, not part of "zoom".
    • ImprobableTruth 5y ago
      Even downscaling uses interpolation, but sure. The zoomed in part definitely wasn't shown at its native resolution though. And bilinear interpolation is as simple as you can get besides nearest neighbor, yet it still has the potential to introduce wrong information/cause artifacting. So even in the "CSI" sense, zooming can cause issues (unless you want to argue that only nearest neighbor is CSI 'zooming'? But then not even browsers do only CSI 'zooming').
  • _djo_ 5y ago
    As Twisol said, zooming doesn't inherently require interpolation. But when it does require interpolation, it's usually an extremely simple and well-understood form like nearest neighbour interpolation that's not going to result in things like faces being inserted. It also only uses the available data in the image itself on which to work. It's fundamentally different from neural network-driven inference and interpolation that attempts to fill in pixels using evidence from other images that the network has been trained on.
    • iainmerrick 5y ago
      How is a non-expert, and somebody whose job specifically requires them to be sceptical and to question unstated assumptions, supposed to be sure of that?
      • _djo_ 5y ago
        It's a simple enough thing to verify, or require the defence (in this case) to substantiate the claim without throwing out the method of showing evidence entirely. Courts have to deal with questions like this all the time and handle them well enough. Technology isn't magic, nor do we have to go down a rabbit hole on each point about what might be there rather than what is there.
        • A4ET8a8uTh0 5y ago
          It is not magic, but, as other posters alluded, sometimes it can be merely an educated guess. It is hard to accept a life changing verdict based on a guess.. even if it is an educated one. So no, each time a given technique is used, the way it works has to be explained so that a decision based on facts of the case is made.
          • _djo_ 5y ago
            Nothing wrong with that, but a common sense explanation by an expert witness ought to be enough. Does Apple need to be dragged into each and every case to testify as to how pinch to zoom works, as was demanded here? Courts have established mechanisms for handling technical questions around evidence. It's not like any of this is new.
            • jtbayly 5y ago
              All that was required was an expert witness, right? So what’s the problem?
              • _djo_ 5y ago
• ClumsyPilot 5y ago
  Last time we in UK court assumed that prosecution's claims about technology could be trusted, we sent 200 (!!) innocent people to jail https://en.m.wikipedia.org/wiki/British_Post_Office_scandal https://en.m.wikipedia.org/wiki/British_Post_Office_scandal