Re: 1-D Gaussian multiplier/convolution function around line in image.

Posted by Herbie on Jan 26, 2019; 8:48am
URL: http://imagej.273.s1.nabble.com/1-D-Gaussian-multiplier-convolution-function-around-line-in-image-tp5021719p5021720.html

Good day Ethan,

you may use the ImageJ-functionality that is accessible from "Process >>
Math >> Macro..."

Enter the following code to the Code-line:

b=0.001; v=v*3*exp(-b*(y-h*0.5)*(y-h*0.5));

This Image-Math macro works for 32bit images and the Gauss-width is
defined by variable b.

The Gauss-width should *not* be called bandwidth if your image isn't a
Fourier-spectral signal.

Of course, the Gauss-function acts as a weighting window, i.e. it does
*not* perform a convolution!

Regards

Herbie

::::::::::::::::::::::::::::::::::::::::::::
Am 26.01.19 um 02:36 schrieb Cohen, Ethan D:

>
> I have an image, where I want to vertically weight the intensity the pixels, by a 1-D Gaussian function around a horizontal line ROI in the image, so that the peak is 3X the original intensity, with a Gaussian ½ bandwidth of say 15 pixels in the Y direction.
>
> Something like, v=3v* exp (-b*(y-y0)^2  -1*(y-y0));?
>
> Or maybe ImageJ already has a feature for 1-D Gaussian weighting (not blur)?   I guess this is sort of a 1-D convolution.
>
> Is there a function already in ImageJ to do this?
> I suppose I could make some sort of weighting matrix, but it seems rather painful.
>
> Ethan.
>
>
> Ethan Cohen, Ph.D.
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