Posted by
Jacqueline Ross on
Jul 18, 2006; 7:40am
URL: http://imagej.273.s1.nabble.com/Optical-artefact-removal-tp3702076.html
Dear All,
I have had an enquiry from someone from another Department who has an
artefact affecting their imaging which looks like a diffraction effect
(e.g. Newton rings) when doing transmitted light microscopy.
I had a look at their microscope and camera system and even when Koehler
illumination is set up properly, you still get this effect. The
microscope is a rather old Nikon inverted microscope with a Coolpix
attached. The objectives, (phase contrast), are not infinity corrected
and I'm assuming that there is also a problem with the tube length for
the camera. The rings are there irrespective whether specimens are on
glass or in plastic dishes. I don't think much can be done optically
(correct me if I'm wrong) but I wondered if some image processing could
help.
My ImageJ question is this:
Is it possible to use some kind of image processing (e.g. image
subtraction) to remove this artifact? I have tried a few things out
(e.g. Image calculator, rolling ball) without much success so far.
I have posted 2 images at the following address:
http://www.health.auckland.ac.nz/biru/exptal_images/index.html There are
also links to larger images although the original images are even larger
than these.
Please note that I do know that these images are appalling! I asked one
of the students to send me one image with tissue (glass slide) and one
without at the same focal plane and this is what I got! I don't think
they set up the microscope very well. However, you can see the rings
clearly on both images so I hope they will inspire someone to suggest a
solution.
I would be very pleased to hear of any potential solutions.
Cheers,
Jacqui.
Jacqueline Ross
Biomedical Imaging Research Unit
School of Medical Sciences
Faculty of Medical & Health Sciences
The University of Auckland
Private Bag 92019
Auckland, NEW ZEALAND
Tel: 64 9 373 7599 Ext 87438
Fax: 64 9 373 7484
http://www.health.auckland.ac.nz/biru/<
http://www.health.auckland.ac.nz/biru/>