Contour lines by density of particles

[Josecito]

Hello everybody,

I'm working in a study to count particles on drone's image.

After the threshold adjustment and the particles analysis, I want to represent the density of particles using the contour lines.

Where the image has the highest density of particles I want to represented by a red color, where the image has the lowest density I want to represented by yellow.

Thank you very much in advance for your help

Josecito

[Herbie]

Josecito,

any solution depends on how you define and compute the particle density.

Best

Herbie

::::::::::::::::::::::::::::::::::::::
Am 04.04.16 um 18:19 schrieb Josecito:

> Hello everybody,
>
> I'm working in a study to count particles on drone's image.
>
> After the threshold adjustment and the particles analysis, I want to
> represent the density of particles using the contour lines.
>
> Where the image has the highest density of particles I want to represented
> by a red color, where the image has the lowest density I want to represented
> by yellow.
>
> Thank you very much in advance for your help
>
> Josecito
>
>
>
> -----
> Josecito
> --
> View this message in context: http://imagej.1557.x6.nabble.com/Contour-lines-by-density-of-particles-tp5016061.html
> Sent from the ImageJ mailing list archive at Nabble.com.
>
> --
> ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>

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[Josecito]

Hello,

We want to have the possibility to define de particle density (nb of particle / square pixels).

For example :


the average particle is 5 pixels
my density will be defined by an area of 50px x 50px or 100px x 100px

The image has more than 8400 particles.

With these parameters how can we represent the contour lines in colors in fonction of the density?
Can we find a macro which can do this automatically ?

Thanks for your help.

Josecito.

[Herbie]

Josecito,

it seems that the particles are difficult to define. Can they overlap?

How do you think you can count them?
(Evidently you have to count them for getting "nb of particle / square
pixels".)

Best

Herbie

::::::::::::::::::::::::::::::::::::::
Am 08.04.16 um 18:29 schrieb Josecito:

> Hello,
>
> We want to have the possibility to define de particle density (nb of
> particle / square pixels).
>
> For example :
> <http://imagej.1557.x6.nabble.com/file/n5016084/Count_Masks_of_DSC01054.jpg>
>
> the average particle is 5 pixels
> my density will be defined by an area of 50px x 50px or 100px x 100px
>
> The image has more than 8400 particles.
>
> With these parameters how can we represent the contour lines in colors in
> fonction of the density?
> Can we find a macro which can do this automatically ?
>
> Thanks for your help.
>
> Josecito.
>
>
>
>
>
>
>
>
>
>
> -----
> Josecito
> --
> View this message in context: http://imagej.1557.x6.nabble.com/Contour-lines-by-density-of-particles-tp5016061p5016084.html
> Sent from the ImageJ mailing list archive at Nabble.com.
>
> --
> ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>

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

[Michael Schmid]

Hi Josecito,

One possible solution:
- Find Maxima with single-point output (gives you 1 pixel per particle);
assumes that particles do not overlap.
- Convert to 32 bits and divide by 255.
- Smooth with a method of your choice (e.g. Process>Filters>Mean) and
large radius. The values will be in particles per pixel now.
- Divide by the pixel area (in physical units, e.g. square meters) to
get particles per area, if desired. Multiply by 50*50=2500 instead if
you want to know the number of particles in an area of 50x50 pxl.
- Use a Contour plotting plugin of your choice, e.g.
   http://rsb.info.nih.gov/ij/plugins/contour-plotter.html

For the last step, you can also threshold the image at different levels,
use 'Create Selection' and add all selections to the overlay or the ROI
Manager.

Michael
________________________________________________________________
On 2016-04-08 18:29, Josecito wrote:

> Hello,
>
> We want to have the possibility to define de particle density (nb of
> particle / square pixels).
>
> For example :
> <http://imagej.1557.x6.nabble.com/file/n5016084/Count_Masks_of_DSC01054.jpg>
>
> the average particle is 5 pixels
> my density will be defined by an area of 50px x 50px or 100px x 100px
>
> The image has more than 8400 particles.
>
> With these parameters how can we represent the contour lines in colors in
> fonction of the density?
> Can we find a macro which can do this automatically ?
>
> Thanks for your help.
>
> Josecito.

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