Re: Maxima in a plot profile

Posted by Jerome Mutterer-3 on Jun 28, 2013; 7:49am
URL: http://imagej.273.s1.nabble.com/Maxima-in-a-plot-profile-tp5003690p5003691.html

Hi Eric,

You must have Edit > Options > Profile Plot Options > Interpolate line
profiles option checked.
Uncheck it if you want uninterpolated pixel values.

The pixel values along a line are retrieved like this:
https://github.com/fiji/imagej1/blob/master/ij/gui/Line.java#L394

For 1 pixel wide lines like yours the interpolation code is there:
https://github.com/fiji/imagej1/blob/master/ij/process/ImageProcessor.java#L962

and finally calls the getInterpolatedValue(x,y) method here:
https://github.com/fiji/imagej1/blob/master/ij/process/ImageProcessor.java#L1694

Sincerely,

Jerome.

On 28 June 2013 08:44, Eric Denarier <[hidden email]> wrote:

> Dear All,
> I would like to know how the values are calculated in a plot profile :
> I have a small image (Stack-2.tif) in which I draw a line over the pixel
> of maximum intensity (value : 2068).
> The line is traced
>  If I use Analyze/Plot Profile and list the values from a 1 pixel width
> line the maximum is 1921.58 (Values on the left of plot profile.png). On
> the right it's with a width of 3 pixels.
> How does the values are calculated ? How can I get the real max value ( in
> this case 2068) of a line across a picture ?
>
> Thanks for your comment
>
> -- ich
>
> Eric Denarier
> Grenoble Institut des Neurosciences
> Inserm U836
> Chemin Fortuné Ferrini
> 38700 La Tronche
> France
>
>
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>
> http://neurosciences.ujf-**grenoble.fr/<http://neurosciences.ujf-grenoble.fr/>
>
>
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