Hi Mario,
of course, the gold standard is flat field (and dark frame) correction.
If you can't do that because your images were acquired long time ago or
at a system where you have no access any more:
The very simple way to mitigate smooth variations of illumination in
bright-field images with mostly background is 'Subtract background',
best using the sliding paraboloid option.
If you have a linear detector and zero intensity roughly corresponds to
a zero pixel value, duplicate the image, use 'subtract background' with
'create background' (and 'sliding paraboloid'), and divide the original
by this background (32-bit float output).
If you have many images taken with the same setup, you could have them
in a stack (import image sequence) and use Image>Stacks>z Project with
'max intensity'. If required, use the 'create background' option of
'subtract background' to remove remaining 'holes' (where all images of
the stacks have had foreground objects). Some blurring or a polynomial
fit [1] may help to smooth it.
Michael
[1] https://imagejdocu.list.lu/plugin/filter/fit_polynomial/start
________________________________________________________________
On 27.06.25 08:33, Faretta Mario Romolo wrote:
Hi all,
I would like testing two different plugins for correction of uneven
illumination, BASIC and CIDRE. However, while I have no problem on BASIC, I'm
not able to run CIDRE (win 11 imageJ v1.54 java 1.8). When I try ro build a
model after a couple of messages that announce successful reading of the input,
nothing happens in the destination directory where results have to be written.
Any experience on it?
Do you any alternative for the same goal , i.e. retrospective flatfield
correction?
Many thanks
Mario
Mario Faretta
Imaging Development Unit Director
Department of Experimental Oncology
European Institute of Oncology
via Adamello 16
20139 Milan
Italy
Phone: +390294375027
email: [email protected]
[5x1000]<http://www.ieo.it/it/SCIENCE-IN-SOCIETY/Le-nostre-iniziative/5-per-mille/>
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