Re: median filter that preserves peaks

Posted by Gabriel Lapointe-4 on
URL: http://imagej.273.s1.nabble.com/median-filter-that-preserves-peaks-tp5004693p5004708.html

Hi Neil,
I guess you could always try a bandpass FFT filter. It's a bit more
complicated than a median filter but once you managed all the tweaking you
can get very good results.

*Gabriel Lapointe, M.Sc.*
Lab Manager / Microscopy Specialist
Concordia University, Biology Department
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2013/9/6 Neil Fazel <[hidden email]>

> Thanks. I will look into that.
>
> I have attached a montage of 3 profile plots using 1) the original image,
> 2) image after applying median filter with radius 0.5, and 3) image after
> median filter with radius 1. You can see how the Y axis maximum of the
> plots goes from 3.28 to 3.15 to 3.13; the high frequency component has been
> reduced (good) at the same time that the peaks have been flattened (bad).
>
> I guess what I'm looking for is a filter that replaces local outliers
> (i.e. outliers in a neighborhood 2-3 pixels in each direction) with the
> median, but preserves them if they remain outliers in a larger
> neighborhood, which indicates that they are not noise but actual peak
> signal.
>
> Neil
>
>
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