cross-posted from: https://programming.dev/post/37278389

Optical blur is an inherent property of any lens system and is challenging to model in modern cameras because of their complex optical elements. To tackle this challenge, we introduce a high‑dimensional neural representation of blur—the lens blur field—and a practical method for acquisition.

The lens blur field is a multilayer perceptron (MLP) designed to (1) accurately capture variations of the lens 2‑D point spread function over image‑plane location, focus setting, and optionally depth; and (2) represent these variations parametrically as a single, sensor‑specific function. The representation models the combined effects of defocus, diffraction, aberration, and accounts for sensor features such as pixel color filters and pixel‑specific micro‑lenses.

We provide a first‑of‑its‑kind dataset of 5‑D blur fields—for smartphone cameras, camera bodies equipped with a variety of lenses, etc. Finally, we show that acquired 5‑D blur fields are expressive and accurate enough to reveal, for the first time, differences in optical behavior of smartphone devices of the same make and model.

  • Seefra 1@lemmy.zip
    link
    fedilink
    arrow-up
    32
    arrow-down
    1
    ·
    edit-2
    1 day ago

    It’s old news that you should never use the same camera for two images that need separate identities.

    The same applies to radio transmitters and every analogue medium like probably microphone or preamp or ADC.

    Anything that doesn’t work on purely digital domain is most likely traceable and I wouldn’t be surprised if proprietary software like Adobe started embedding hidden fingerprints into their files to “enforce their copyright” or “better collaborate with law enforcement”

    I tend to complain that ROMs like Graphene OS don’t allow spoofing IMEI which should be basic functionally of every privacy-enabled phone. Yet if you require real privacy the electronic “fingerprint” of the radio itself is probably enough to track someone if they really want to.

    There’s also a thing where they can track someone’s time and location just from listening to oscillations on the utility power’s frequency

    • Pup Biru@aussie.zone
      link
      fedilink
      English
      arrow-up
      2
      ·
      8 hours ago

      The same applies to radio transmitters and every analogue medium like probably microphone or preamp or ADC.

      exactly why when you buy any halfway decent mic there’s the option to buy them in sets: they’ll have come off the production line together so that their imperfections are as close to each other as possible so that they sound as identical as they can be

    • Mgineer@lemmy.ml
      link
      fedilink
      arrow-up
      2
      ·
      10 hours ago

      Anything that doesn’t work on purely digital domain is most likely traceable

      at this point I believe that digital is easier to trace as every device ever connected to the Internet or connected to a device that has, has probably been bugged

    • irmadlad@lemmy.world
      link
      fedilink
      English
      arrow-up
      3
      ·
      1 day ago

      It’s old news that you should never use the same camera for two images that need separate identities.

      Sanatize metadata and Exif data?

      • Seefra 1@lemmy.zip
        link
        fedilink
        arrow-up
        10
        ·
        1 day ago

        That’s probably enough to stop your online mates from doxing you, but a powerful enough adversary can trace the little unique nuanced fingerprints that a camara lens introduces to the picture, and compare it with images from other sources like social media.

        There are are many steps that can introduce patterns, like the way the lens blurs as explained in the article, sensor readout noise patterns, a speckle of dust, scratches, I bet chromatic aberrations are probably also different between multiple copies of the lens.