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Re: quantifying focal adhesions

Posted by Joel Sheffield on Nov 12, 2009; 5:10pm
URL: http://imagej.273.s1.nabble.com/quantifying-focal-adhesions-tp3690483p3690485.html

Hi,

One more possibility is to try to normalize the background by using
the FFT bandpass filter.  You may be able to filter out the
background variation (essentialy low frequency components, while
retaining the small points (the high frequency components.)
Joel


> Hello,
> I have a similar probem.There are several ways to deal with it.
> You
> can try the "Process=>Binary=>Find Maxima" command which finds the
> local maxima in brightness within certain noise tollerance limits
> (say
> for example 40 brightness
> levels)(http://rsb.info.nih.gov/ij/docs/menus/process.html#binary)
> .
> You can try also try either the build in "Subtract background"
> command
> or the "Background subtractor" plugin (
> http://www.mosaic.ethz.ch/Downloads/bgs ). The two latter produce
> not
> a thresholded binary image but keep the format of the images
> instead,
> however the filtered images are very easily thresholded.
> If this still doesn't work either you may want to try some more
> advanced form of morphological filtering (for example the
> "GreyScaleTopHat"or "Find regional Maxima" macros from Landini's
> Morphology collection of plugins is very useful"
> Good luck!
> --
>  Stoyan P. Pavlov, MD
> Departament of Anatomy, Histology and Embryology
> Medical University "Prof. Dr. Paraskev Stoyanov", Varna
> Prof. Marin Drinov Str.55
> 9002 Varna
>  Bulgaria
> Tel: +359 (0) 52 - 677 - 050 #2638
> e-mail: [hidden email]
>
> On Thu, Nov 12, 2009 at 4:52 AM, David Knecht ATT
> <[hidden email]> wrote:
> > We are trying to come up with a way to quantify the difference in
> the
> > number/size of focal adhesions in cells under different
> conditions.  The
> > images were taken on a widefield scope and so there is significant
> and
> > variable cellular background fluorescence.  The focal adhesions
> themselves
> > have pixel values above the local background that surrounds them,
> so they
> > are easy to pick out by eye, but you can't threshold easily
> because there
> > vary in intensity and there are other areas of the cell which have
> the same
> > or higher and lower pixel values than the focal adhesions we want
> to target.
> >  Is there a way of classifying/thresholding that will compare
> structures to
> > the local background surrounding it so as to allow it to be
> identified and
> > quantified?  Thanks- Dave
> >
> > Dr. David Knecht
> > Department of Molecular and Cell Biology
> > Co-head Flow Cytometry and Confocal Microscopy Facility
> > U-3125
> > 91 N. Eagleville Rd.
> > University of Connecticut
> > Storrs, CT 06269
> > 860-486-2200
> > 860-486-4331 (fax)
> >
>
>
>
> --
> Dr. Stoyan P. Pavlov, MD
> Departament of Anatomy, Histology and Embryology
> Medical University "Prof. Dr. Paraskev Stoyanov", Varna
> Prof. Marin Drinov Str.55
> 9002 Varna
>  Bulgaria
> Tel: +359 (0) 52 - 677 - 050 #2638
> e-mail: [hidden email]


--
Joel B. Sheffield, Ph.D.
Biology Department, Temple University
1900 North 12th Street
Philadelphia, PA 19122
[hidden email]
(215) 204 8839, fax (215) 204 0486
http://astro.temple.edu/~jbs