Wednesday, May 02, 2018

FAU Develops Pixel Rotation that Improves Resolution and Reduces Aliasing

Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany (FAU) proposes a low fill factor pixels pseudo-randomly rotated in the pixel array to improve resolution by a factor of 4 and avoid alias artifacts. Microlens usage and complicated signal routing in the pixel array are not mentioned:

Posted by Vladimir Koifman at 19:45

8 comments:

  1. AnonymousMay 2, 2018 at 8:50 PM

    Isn't this a really old idea? I remember proposing it many years ago, but I believe I found I wasn't the first.

    One big challenge would be PRNU resulting from variations in photodiode capacitance.

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    1. tentnerMay 3, 2018 at 6:01 AM

      I fail to understand how this should work? Especially when colors (Bayer pattern) come into play... Would they generate e.g. a 3840 x 2160 image from a 1920 x 1080 Bayer pattern?

      Delete
    2. AnonymousMay 3, 2018 at 11:10 AM

      I believe it only adds a layer of random blur over the CFA to reduce moiré, at the cost of details. The example shows less moiré and less details/more random smudge.

      Delete
  2. AnonymousMay 2, 2018 at 10:32 PM

    Weird example photo, the red zoom in looks better on the left but the blue zoom in looks better on the right.

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    1. AnonymousMay 3, 2018 at 11:46 AM

      I'm with you there. The "improved image" seems to suffer from some unfortunate JPEG/DCT compression artifacts which make it look a lot worse.

      Delete
  3. AnonymousMay 3, 2018 at 6:41 AM

    With lens CRA change and Bayer pattern, it seems to be something working only in a perfect world.

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  4. Albert Theuwissen - Harvest ImagingMay 4, 2018 at 9:53 AM

    By itself it is an interesting idea, because MTF and alias depend on the shape of the light sensitive part of the pixel (although a micro-lens can kill this effect). But I think that the cross talk between the pixels is going to be non-uniform across the array and that will generate some other beautiful issues. But a very useful topic to understand the ins and outs of MTF, alias and cross-talk.

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  5. Steven HNovember 8, 2018 at 7:18 PM

    I did a lot of this in my PhD thesis back in 1993: https://www.era.lib.ed.ac.uk/handle/1842/14043

    Have a look at page 200 onwards for extensions of the idea, just cite me :-)

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