Posted by
Jacob Keller-2 on
Oct 30, 2018; 3:23pm
URL: http://imagej.273.s1.nabble.com/Frequency-Filtering-in-Time-Dimension-tp5021367p5021374.html
>
> do you have simply a 1D data set or an image stack, with slices for
> different times?
>
The latter--image stack, one plane over time.
- In the second case, you can use Process>Filters>Gaussian Blur 3D and
> specify the x and y sigma as zero.
> For high-pass filtering, you would have to duplicate the stack first and
> then subtract the filtered image.
>
Ah, this is a great idea--I will try it out. How can I figure out the
relationship between sigma and the desired frequency cutoff? For example,
let's say the stack has 120 frames per period--what sigma value should be
input?
Thanks very much for these suggestions--I think they are going to be
very helpful,
Jacob
If you rather want moving averages or a median, you can reslice the
> stack (Image>Stacks>Reslice) to have the time direction in x or y and
> apply the 'Fast Filters' plugin, which can do 1D filtering. Then Reslice
> to make time the z axis again.
> The 'Fast Filters' plugin also has an option to subtract the filtered
> image (i.e., highpass operation)
>
>
> Michael
> ________________________________________________________________
> On 29.10.18 20:51, Jacob Keller wrote:
> > Hi All,
> >
> > is there a way to do high-pass/low-pass filtering in the time dimension?
> Or
> > a suggestion for a workaround?
> >
> > All the best,
> >
> > Jacob Keller
>
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