How does AND work?

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How does AND work?

wirthvolker
Hi,
sorry to ask a (probably) stupid question, but I cannot find a helpful
text or figure it out myself - and it might help others who do not
dare to ask ;)

I have two images and would like to look at _co-localization_. So, my
idea was to use the _AND_ operator from the image calculator for this.
Now I realize, that I do not understand what it actually does, as it
takes a greyscale (I guess color makes it even more complicated) and
results in another greyscale image.

So far, I know only the Boolean conjunction, giving:
0 AND 0  =  0, 0 AND 1  =  0, 1 AND 0  =  0 and 1 AND 1  =  1

Is there anyone who can tell me what AND means in this context or
where I can read about it (and maybe the other calculator funcions,
too)? Any hint will be appreciated :)

Best regards,
Volker
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Re: How does AND work?

Stephan Saalfeld
To my knowledge, it does a bitwise AND (a&b) as executed in

http://pacific.mpi-cbg.de/cgi-bin/gitweb.cgi?p=ImageJA.git;a=blob;f=ij/process/ByteBlitter.java#l131

which does not seem to make too much of a sense in your application(?)

What do you actually expect the operation to do for you?

Best,
Stephan




On Tue, 2010-10-26 at 10:58 +0200, Volker Wirth wrote:

> Hi,
> sorry to ask a (probably) stupid question, but I cannot find a helpful
> text or figure it out myself - and it might help others who do not
> dare to ask ;)
>
> I have two images and would like to look at _co-localization_. So, my
> idea was to use the _AND_ operator from the image calculator for this.
> Now I realize, that I do not understand what it actually does, as it
> takes a greyscale (I guess color makes it even more complicated) and
> results in another greyscale image.
>
> So far, I know only the Boolean conjunction, giving:
> 0 AND 0  =  0, 0 AND 1  =  0, 1 AND 0  =  0 and 1 AND 1  =  1
>
> Is there anyone who can tell me what AND means in this context or
> where I can read about it (and maybe the other calculator funcions,
> too)? Any hint will be appreciated :)
>
> Best regards,
> Volker
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Re: How does AND work?

wirthvolker
Hi Stephan,
thanks for the answer and the link!

> which does not seem to make too much of a sense in your application(?)

Jep...

> What do you actually expect the operation to do for you?

My idea was to do a quick colocalisation analysis with a simpler
method than the WCIF plugins
(http://www.uhnresearch.ca/facilities/wcif/imagej/colour_analysis.htm)
- which are probably the best available solution. My idea was to use
the calculator to see where I have signal in both images - which would
probably end up in a messy image without the information that I want.

But at least I learned more about the AND!

Best
Volker
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Re: How does AND work?

Soriano.Joaquim
In reply to this post by wirthvolker
Hi
AND Works exactly as you noted, but imagej interprets (after
thresholding) 0 as 0 and 1 as 255.
Make sure you threshold your images properly before running Booleans.
If one of your images (or both) are not binary, then AND may act as an
mathematic multiplication.
Wish this helps.

-----Mensaje original-----
De: ImageJ Interest Group [mailto:[hidden email]] En nombre de
Volker Wirth
Enviado el: martes, 26 de octubre de 2010 10:58
Para: [hidden email]
Asunto: How does AND work?

Hi,
sorry to ask a (probably) stupid question, but I cannot find a helpful
text or figure it out myself - and it might help others who do not
dare to ask ;)

I have two images and would like to look at _co-localization_. So, my
idea was to use the _AND_ operator from the image calculator for this.
Now I realize, that I do not understand what it actually does, as it
takes a greyscale (I guess color makes it even more complicated) and
results in another greyscale image.

So far, I know only the Boolean conjunction, giving:
0 AND 0  =  0, 0 AND 1  =  0, 1 AND 0  =  0 and 1 AND 1  =  1

Is there anyone who can tell me what AND means in this context or
where I can read about it (and maybe the other calculator funcions,
too)? Any hint will be appreciated :)

Best regards,
Volker

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Re: How does AND work?

Albert Cardona-2
In reply to this post by wirthvolker
Hi Volker,

To perform scientifically meaningful colocalization analysis, please see:

http://pacific.mpi-cbg.de/wiki/index.php/Colocalization_Analysis

Best,

Albert
--
http://albert.rierol.net
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Re: How does AND work?

wirthvolker
Hi Albert,
thanks for the link, that looks like a very good point to start from.
BTW: The links QuantitativeColocAnalysis
(https://info.med.tu-dresden.de/MTZimaging/images/2/25/White_QuantitativeColocAnalysis0408a.pdf)
and Quantitative Imaging
(https://info.med.tu-dresden.de/MTZimaging/images/6/63/White_QuantitativeColocAnalysis0408b.pdf)
in the first paragraph are dead - do you know if they once led to
papers that I might get from somewhere else?
Best,
Volker
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Re: How does AND work?

Albert Cardona-2
2010/10/27 Volker Wirth <[hidden email]>:
> Hi Albert,
> thanks for the link, that looks like a very good point to start from.
> BTW: The links QuantitativeColocAnalysis
> (https://info.med.tu-dresden.de/MTZimaging/images/2/25/White_QuantitativeColocAnalysis0408a.pdf)
> and Quantitative Imaging
> (https://info.med.tu-dresden.de/MTZimaging/images/6/63/White_QuantitativeColocAnalysis0408b.pdf)
> in the first paragraph are dead - do you know if they once led to
> papers that I might get from somewhere else?


Dan White, do you know where the above PDFs are now?

Albert

--
http://albert.rierol.net
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Re: How does AND work?

dscho
Hi,

On Wed, 27 Oct 2010, Albert Cardona wrote:

> 2010/10/27 Volker Wirth <[hidden email]>:
> > thanks for the link, that looks like a very good point to start from.
> > BTW: The links QuantitativeColocAnalysis
> > (https://info.med.tu-dresden.de/MTZimaging/images/2/25/White_QuantitativeColocAnalysis0408a.pdf)
> > and Quantitative Imaging
> > (https://info.med.tu-dresden.de/MTZimaging/images/6/63/White_QuantitativeColocAnalysis0408b.pdf)
> > in the first paragraph are dead - do you know if they once led to
> > papers that I might get from somewhere else?
>
>
> Dan White, do you know where the above PDFs are now?

I think the current version is to be found here:

https://ifn.mpi-cbg.de/wiki/ifn/index.php/Teaching_Material#IPF_Image_Processing_Courses

Ciao,
Johannes