Gaussian blur before or after Background correction?

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Gaussian blur before or after Background correction?

foxtango
Hi everybody,

In some of my (microscopic) images the gain was set too high. I have to
apply a Gaussian blur. I also have empty images and plan to apply a
Background correction by division. Should I apply the Gaussian blur before
(a) or after (b) Background correction?
(a) Gaussian blur applied to the image and empty image separately
(b) Gaussian blur applied to the corrected image

Thank you, Thomas

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Thomas
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Re: Gaussian blur before or after Background correction?

Herbie
Greetings Thomas,

before commenting your a-c questions it would be important to understand

A) what "the gain was set too high" really means (overexposure?, clipping?)

B) why you think a Gaussian lowpass will or can compensate for the high
gain effects.

Best

Herbie

::::::::::::::::::::::::::::::::::::::::::::
Am 31.07.20 um 22:32 schrieb Thomas Fischer:

> Hi everybody,
>
> In some of my (microscopic) images the gain was set too high. I have to
> apply a Gaussian blur. I also have empty images and plan to apply a
> Background correction by division. Should I apply the Gaussian blur before
> (a) or after (b) Background correction?
> (a) Gaussian blur applied to the image and empty image separately
> (b) Gaussian blur applied to the corrected image
>
> Thank you, Thomas
>
> --
> ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>

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Re: Gaussian blur before or after Background correction?

Arne Seitz
In reply to this post by foxtango
Hi Thomas,

your questions is difficult to answer without having access to the images.

A Gaussian filter can be used in order to remove high frequency noise. If such noise is present in the image and the background image the filter should be applied to both images before the image division. In case there is no high frequency noise in the background image the Gaussian filter has almost no effect and can be omitted.

Cheers
Arne
 


-----Original Message-----
From: ImageJ Interest Group <[hidden email]> On Behalf Of Thomas Fischer
Sent: Freitag, 31. Juli 2020 22:33
To: [hidden email]
Subject: Gaussian blur before or after Background correction?

Hi everybody,

In some of my (microscopic) images the gain was set too high. I have to apply a Gaussian blur. I also have empty images and plan to apply a Background correction by division. Should I apply the Gaussian blur before
(a) or after (b) Background correction?
(a) Gaussian blur applied to the image and empty image separately
(b) Gaussian blur applied to the corrected image

Thank you, Thomas

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

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