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Lens-Free Flat Cameras Make Use of Pinhole Technology (npr.org)

Posted by yaelk on from the what-do-you-see-through-your-lens dept.

RhubarbPye writes: As reported on NPR, "Engineers in Texas are building a camera that can make a sharp image with no lens at all." By incorporating millions of individual pinholes with photoreceptors and postprocessing software, this camera system has been reduced to minimal thickness. Cameras in the wallpaper? A new phase of wearable cameras? What other applications for this technology could be developed?

4 of 65 comments (clear)

  1. Dynamic range? by RightwingNutjob · · Score: 4, Insightful

    TL;DR. Most uncooled camera chips give you maybe 10 or 11 bits of dynamic range, and light is subject to Poisson noise, meaning the brighter a pixel, the noiser it is in absolute (not relative) terms. If you have to solve a big giant matrix inversion to do the job of a collimating lens, you're composing each pixel as a sum of many others instead of just itself, some of them being way brighter than the reconstructed image, meaning your reconstructed pixel is always noisier. Cool idea, and certainly has its applications, but the best images will always come from big fat optics.

    1. Re:Dynamic range? by Arkh89 · · Score: 4, Insightful

      No. First, on these you are mostly limited by the thermal noise of the sensor which is miles above the photon noise for this application. Then you are still thinking that a pixel receives the same flux (power per surface area) as a traditional camera. This is not correct as each of the pixels collect flux from a much larger angular portion of the scene (due to the lack of optical focusing).

    2. Re:Dynamic range? by Ungrounded+Lightning · · Score: 4, Informative

      If you have to solve a big giant matrix inversion to do the job of a collimating lens, you're composing each pixel as a sum of many others instead of just itself, some of them being way brighter than the reconstructed image, meaning your reconstructed pixel is always noisier.

      Not really.

      When you average a large number of samples the noise tends to partially cancel out while the signal keeps adding up. Though the noise goes up with more samples, the signal goes up more, improving the signal to noise ratio. Even if you end up adding in some bright signals, with extra noise, that's still stomped by signal when you have enough samples.

      --
      Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
  2. Nothing is new under the sun? by Lluc · · Score: 4, Interesting
    The way the NPR article describes this, it is no different from Uniformly Redundant Arrays, i.e. Coded Aperture Imaging: see https://en.wikipedia.org/wiki/... If you look at the 1998 paper, "Uniformly Redundant Arrays" by Busboom et al, the first sentence describes work from the 1960s:

    Coded aperture imaging (CAI) (Mertz and Young, 1961; Dicke, 1968) has matured as a standard imaging technique in X–ray and Gamma-ray astronomy. It is capable of combining high angular resolution with good photon collection efficiency by using a mask consisting of transparent and opaque elements placed in front of a position sensitive detector (Figure 1).

    So is the only innovation here using more pinholes, more pixels, and more processing than were around in the 1990s?