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Re: [OM] Megapixels and detail in images

Subject: Re: [OM] Megapixels and detail in images
From: "Wayne Harridge" <wayne.harridge@xxxxxxxxxxxxxxxxxxx>
Date: Fri, 16 Sep 2016 21:31:59 +1000
Thanks Mike !

...Wayne



-----Original Message-----
From: olympus
[mailto:olympus-bounces+wayne.harridge=structuregraphs.com@xxxxxxxxxxxxxxxxx
] On Behalf Of Mike Gordon via olympus
Sent: Friday, 16 September 2016 10:28 AM
To: olympus@xxxxxxxxxxxxxxxxx
Cc: usher99@xxxxxxx
Subject: Re: [OM] Megapixels and detail in images

<<Moose, just a query about deconvolution sharpening:
<<Does the algorithm for deconvolution take into account the lens used


Very late and trying to get home.  In brief, it seems clear DXO uses "blind"
R-L deconvolution but weights it where the lens in softest with their
profiles--so yes, it does take the lens into effect but the algorithm is not
really changed, just how much is applied.
It likely assumes the PSF (point spread function)  is   Gaussian blur as it
works well and the Gaussian deconvolution kernel is fast to compute.  FM and
Topoz in Focus likely uses blind R-L deconvolution with a Gaussian
assumption for the PSF.  
I have not used Topaz but is has an option to  suppress ringing artifacts as
well as picking the blur radius.  How well that works I don't know, but
suspect FM is just as good if carefully used in a layer and applied
judiciously. 
Canyon's DLO from their explanation does use the specific PSF from each lens
for aberrations as well as for diffraction--very cool really.  Deconvolution
sharpening  used to undue diffraction effects would not be predicted to work
well, as there is a hard high freq cut off in the data.
In empiric use it does work fine to a degree--long post on this in the past.


http://lists.tako.de/Olympus-OM/2013-05/msg02068.html

Motion blur is a whole other PSF and FM and Topaz allow one to specify this.

Mike
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