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Author Topic: Artifact Zig Zag background noise in Lytro image.


pleecan
lens array
Posts: 78
Artifact Zig Zag background noise in Lytro image.
on: 2012/09/09 01:11

Has anyone seen artifacts in their Lytro images: Zig Zag pattern....
16X Apochromatic Carl Zeiss Jena non microscope RMS objective mounted infront of Lytro unit.
see link.

http://pictures.lytro.com/pleecan/pictures/358751

http://pictures.lytro.com/pleecan/pictures/358745

Is this a software glitch? What is the cause of the interference? Insufficient lighting???
PL



markus
Administrator
Posts: 64
Re: Artifact Zig Zag background noise in Lytro image.
on: 2012/09/13 00:44

I have observed such artefacts also, when trying to take pictures through a stereo microscope. As far as I can tell, it's a software issue that comes into effect with heavily vignetted photos (i.e. pictures that have a strong black ring near the edges). When the algorithm looks for matching pixels across the entire image, it likely can't tell which of all the black pixels in the corners belong to each other...
take this picture for example:



pleecan
lens array
Posts: 78
Re: Artifact Zig Zag background noise in Lytro image.
on: 2012/09/13 03:43

Yes that was also my thoughts... I hope the software engineers are looking at this issue.... maybe they can come up with a setting ie a microscope mode that generates a mask everything in black is ignored. I know how to overcome this! Tell your engineers to increase the optical magnification zoom on the lytro unit to 2X or 3X the current zoom of 8x.... why not set a 40X optical zoom... .... I first thought it was poor lumination but know... I boosted the lighting to such an extent... still get the zig zag artifact... it is actually anoying.... I am also using expensive apochromatic lens to help minimize the chromatic aberrations the purple haze....... personally I would like to see a lytro without its lens... after spending almost $500 on a used lytro... I will not dismantle the lens on the current Lytro.... I think the black background is screwing up the algorithm in the computation of the vector rays. This zig zag artifact needs to be solved as it will cripple the camera for High resolution imaging of the tiny....



pleecan
lens array
Posts: 78
Re: Artifact Zig Zag background noise in Lytro image.
on: 2012/09/14 02:02

More Artifacts...

Notice the artifact is minimized at 8X zoom.... I need more zoom at high magnifications to compensate this zig zag problem

Definitely the black border is throwing the picture algorithm generating artificial NOISE. Please Fix!!!! This will definitely limit the applications at higher magnification...



pleecan
lens array
Posts: 78
Re: Artifact Zig Zag background noise in Lytro image.
on: 2012/09/14 02:21

Example of Artifact 10X Apo objective. So this is Definately a Lytro problem that needs to be solved!

If we zoom in
Problem is minimized! Recomend 16X to 24X optical zoom on Lytro camera as compensation for microscopy.



pleecan
lens array
Posts: 78
Re: Artifact Zig Zag background noise in Lytro image.
on: 2013/01/03 15:37

More Artifacts diagonal lines to right and excessive noise:

https://pictures.lytro.com/pleecan/pictures/506141#pleecan/pictures/506141



pleecan
lens array
Posts: 78
Re: Artifact Zig Zag background noise in Lytro image.
on: 2013/01/03 15:40

Notice the refocus is poor even though when the picture was taken the image was sharp in the viewer... Think the camera needs an optimized setting to cope with low depth of field objects. The refocus over shoots and under shoots the true focal plane... it is confused.
PL



pleecan
lens array
Posts: 78
Re: Artifact Zig Zag background noise in Lytro image.
on: 2013/01/06 18:23

here is another example of severe noise and artifacts with hash markings of non vignetted pic taken at 50X objective:

https://pictures.lytro.com/pleecan/pictures/512815



pleecan
lens array
Posts: 78
Re: Artifact Zig Zag background noise in Lytro image.
on: 2013/01/16 05:51

More Artifacts:
Horizontal lines and alternating diagonal lines interference ....



pleecan
lens array
Posts: 78
Re: Artifact Zig Zag background noise in Lytro image.
on: 2013/01/29 00:36

This shot proves that excessive noise and artifacts like zig zag lines is not due to vignetting effects:

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