Intensity

[AJBell]

Is there a method of calculating the total intensity as define as the SUM
of pixel values bound by an ROI?

Regards

[Fabrice Senger]

Andrew Bell a écrit :
> Is there a method of calculating the total intensity as define as the SUM
> of pixel values bound by an ROI?
>
> Regards
>  
As far I know when you measure integrated density you will get the mean
intensity multiplied by the area of the ROI, wich is pretty much the
intensity over the whole ROI.

Fabrice.

--
Senger Fabrice

[AJBell]

I would like the actual sum of the gray values, as opposed to manipulated
data. The raw data as it were. In order to perform the ID calculation the
macro must calculate the sum, so it should be possible to display the raw
sum.

[S. Pagakis (nimr)]

If the image is uncalibrated (ie in pixels) then the integrated  
density IS the raw sum.  Otherwise it is normalised by the area.


On 24 Feb 2009, at 12:33, Andrew James Bell wrote:

> I would like the actual sum of the gray values, as opposed to  
> manipulated
> data. The raw data as it were. In order to perform the ID  
> calculation the
> macro must calculate the sum, so it should be possible to display  
> the raw
> sum.

*********************************
Stamatis Pagakis Ph.D.
Biological Imaging Unit
Biomedical Research Foundation, Academy of Athens
Soranou Efessiou 4, Athens 115 27 - Greece
M:     [phone]                 W:     [phone]
FAX: [phone]                     [hidden email]

[Hugo A. M. Torres]

I get a very slight different value if I calculate the integrated
optical density if I multiply the mean optical density by ROI area value
compared to the value imageJ outputs.

Is that a rounding problem? Or maybe does imageJ consider stdev error in
the computation?

On Tue, 2009-02-24 at 12:51 +0200, S. Pagakis (nimr) wrote:

> If the image is uncalibrated (ie in pixels) then the integrated  
> density IS the raw sum.  Otherwise it is normalised by the area.
>
>
> On 24 Feb 2009, at 12:33, Andrew James Bell wrote:
>
> > I would like the actual sum of the gray values, as opposed to  
> > manipulated
> > data. The raw data as it were. In order to perform the ID  
> > calculation the
> > macro must calculate the sum, so it should be possible to display  
> > the raw
> > sum.
>
> *********************************
> Stamatis Pagakis Ph.D.
> Biological Imaging Unit
> Biomedical Research Foundation, Academy of Athens
> Soranou Efessiou 4, Athens 115 27 - Greece
> M:     [phone]                 W:     [phone]
> FAX: [phone]                     [hidden email]

--
Hugo Arruda de Moura Torres
==================================
Departamento de Biofísica
Universidade Federal de São Paulo
Rua Botucatu 862 7o. andar
CEP 04023-062 Vila Clementino
São Paulo - SP - Brasil
Tel:[phone] r.220
Fax: [phone]