*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****
As I understand it, in principle there should be no difference. But in
practice there could be a difference depending on the bit depths the
system could handle. For example, early Bio-Rad systems (I'm showing my
age here) could only collect a single image at 8-bit depth, but averaged
into a 16-bit buffer, so you would do much better by averaging (so long
as you saved the final result as 16-bit).
Guy
Optical Imaging Techniques in Cell Biology
by Guy Cox CRC Press / Taylor & Francis
http://www.guycox.com/optical.htm
______________________________________________
Associate Professor Guy Cox, MA, DPhil(Oxon)
Australian Centre for Microscopy & Microanalysis,
Madsen Building F09, University of Sydney, NSW 2006
Phone +61 2 9351 3176 Fax +61 2 9351 7682
Mobile 0413 281 861
______________________________________________
http://www.guycox.net
-----Original Message-----
From: Confocal Microscopy List [mailto:[log in to unmask]]
On Behalf Of Stanislav Vitha
Sent: Friday, 17 June 2011 2:26 AM
To: [log in to unmask]
Subject: averaging vs. accumulation for noise reduction - is there a
difference?
*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****
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
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 10.0.1382 / Virus Database: 1513/3706 - Release Date: 06/15/11
|
