Posted by
Straatman, Kees (Dr.) on
URL: http://confocal-microscopy-list.275.s1.nabble.com/averaging-vs-accumulation-for-noise-reduction-is-there-a-difference-tp6483751p6486973.html
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Very interesting discussion.
I was just wondering. We talk about S/N. If you acquire a single frame for longer I would expect you also accumulate more noise in the image, if you average your signal in each image your sample should be more or less the same while the noise (random) is averaged. So would you not expect a better S/N with averaging when all else is equal?
Kees
Senior Experimental Officer
Centre for Core Biotechnology Services
University of Leicester, UK
http://www.le.ac.uk/biochem/microscopy/home.html-----Original Message-----
From: Confocal Microscopy List [mailto:
[hidden email]] On Behalf Of Stanislav Vitha
Sent: 16 June 2011 17:26
To:
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Subject: averaging vs. accumulation for noise reduction - is there a difference?
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Hallo,
this is a very basic question, but I cannot figure this out from what I have
been reading, so a simple explanation for a non-physicist would be much
appreciated:
Is there a real difference in the improvement of the signal to noise ratio
between frame averaging (or accumulation) and longer dwell times (slower
scan) for a point-scanning confocal witrh a PMT detector?
For instance, using single point scanning confocal, 12-bit acquisition.
a) averaging (or accumulating) 5 frames, 4 microseconds per pixel
b) acquiring a single frame, 20 microseconds per pixel
Assumptions:
no saturation of the detector;
stable environmental conditions, no focus drift, etc
Would it matter (for the dfference between the two scenarios) if it was analog
detection or photon counting detection?
I will run this little test later, but I am curious what you think.
I thought that at least for the photon counting mode, the two important
factors would be the dark counts and the total number of counts detected, so
whether it is acquired in one scan or in 5 scans, it should be the same. My
camera expert here insists that the averaging scheme will give better noise
suppression.
Thanks!
Stan Vitha
Microscopy and Imaging Center
Texas A&M University