Mean gray value of multiple particles

classic Classic list List threaded Threaded
3 messages Options
Reply | Threaded
Open this post in threaded view
|

Mean gray value of multiple particles

mdhiggins
Hello,

I have an gray-scale image of particles on a black background. I want to mean gray values for each particle (as well as other data). If I use 'Analyse particles' I need a thresholded binary image and lose the mean gray scale.

Is there a way out of this dilemma?

Cheers  Michael

--
ImageJ mailing list: http://imagej.nih.gov/ij/list.html
Reply | Threaded
Open this post in threaded view
|

Re: Mean gray value of multiple particles

Christian Goosmann-2
Dear Michael
yes there is. Run analyze particles on the thresholded _original_ image
(with the thresholded pixels shown as a red overlay) after setting the
apropriate measurements (min, max, average etc.). Don't click 'apply' in
the threshold tool before. If you have to use a threshold method that
only returns a binary mask (e.g. auto local threshold), you will have to
send the objects to roi manager and measure the original image from roi
manager afterwards.
Hope this helps
Christian

---
Christian Goosmann
Mikroskopie
Max-Planck-Institut für Infektionsbiologie
Campus Charité Mitte
Charitéplatz 1
10117 Berlin
Tel.: +49 30 28460 388

Michael Higgins wrote:

> Hello,
>
> I have an gray-scale image of particles on a black background. I want to mean gray values for each particle (as well as other data). If I use 'Analyse particles' I need a thresholded binary image and lose the mean gray scale.
>
> Is there a way out of this dilemma?
>
> Cheers  Michael
>
> --
> ImageJ mailing list: http://imagej.nih.gov/ij/list.html

--
ImageJ mailing list: http://imagej.nih.gov/ij/list.html
Reply | Threaded
Open this post in threaded view
|

Re: Mean gray value of multiple particles

mdhiggins
In reply to this post by mdhiggins
Thanks Christian -

Excellent - I would never have thought of that!

Michael

--
ImageJ mailing list: http://imagej.nih.gov/ij/list.html