Gaussian Filter: Sigma ans support

Hello there,
I would like you to help me understanding the gaussian filter and using it effectively for my project.
I am trying to reproduce the thresholded pictures of a micro-computed tomography system. When doing the threshold a gaussian filter was applied with a Gaussian Sigma value = 0.6 and a Support = 2.
Now, as I said, I want to get the exact same picture using imagej, but I did not find a way to do it. When using the Gaussian Blur I can just put the sigma radius (this is the same sigma, so 0.6, right?). How can I set up the Support?
Thank you very much for your aid.

You need to be slightly careful about Sigma, as in some programs it is in units and others it is in pixels. So the 0.6 could mean different things. If they are both in pixels, that just leaves the Support. I assume this means the kernel size, which indicates the cutoff.

I don’t think ImageJ, by default, limits the size of the kernel, though I could be wrong. I only briefly looked it up in the wiki. You may need to use the Convolve… function to artificially limit the scope of the Gaussian filter. To create your kernel:
http://dev.theomader.com/gaussian-kernel-calculator/
Using it in ImageJ:
https://imagej.nih.gov/ij/docs/guide/146-29.html#sub:Convolve

Not sure if this is at all helpful… but maybe. It might be more useful to say what the original program was and give examples. Maybe someone else will be able to be more helpful with that information.

1 Like

Tahnk you very much for your reply and sorry it took me so long to answer. I will try it out and I’ll tell you if it works. If not I’ll keep looking.

I overlooked you last sentence. The original program was a Scanco xCT: http://www.scanco.ch/fileadmin/webmaster_img/Documents/Manual_XtremeCTII.pdf

1 Like