About selections

[Aldo Ramos]

How can I make a polygonal selection for example, and
make another selection inside of it, and fill or clear
the space between them?


       
       
               
___________________________________________________________
Do You Yahoo!?
La mejor conexión a Internet y <b >2GB</b> extra a tu correo por $100 al mes. http://net.yahoo.com.mx 

[Wayne Rasband]

> How can I make a polygonal selection for example,
> and make another selection inside of it, and fill or
> clear the space between them?

Hold down the alt key while making the second selection and it will  
be subtracted from the first. You will then have a donut-shaped  
compound selection that can be filled, cleared or measured.

-wayne

[Liu, Dongfang (NIH/NIAID) [F]]

I did it, but I still lose the first selection

> ----------
> From: Rasband Wayne
> Reply To: List IMAGEJ
> Sent: Monday, April 17, 2006 10:41 PM
> To: List IMAGEJ
> Subject: Re: About selections
>
> > How can I make a polygonal selection for example,
> > and make another selection inside of it, and fill or
> > clear the space between them?
>
> Hold down the alt key while making the second selection and it will  
> be subtracted from the first. You will then have a donut-shaped  
> compound selection that can be filled, cleared or measured.
>
> -wayne
>
>

[Liu, Dongfang (NIH/NIAID) [F]]

I want to do is that a single fluorescence dot surrounded by two concentric circles (10 pixels and 13 pixels diameter) defining a circle and annulus for the measurement of radial gradients in fluorescence. I need to calculate that the intensity of fluorescence of small concentric circles (10 pixels ) minus the fluorescence intensity of annulus.

I greatly appreciated that people can help me!!!!!

Best regards
Don

> ----------
> From: Rasband Wayne
> Reply To: List IMAGEJ
> Sent: Monday, April 17, 2006 10:41 PM
> To: List IMAGEJ
> Subject: Re: About selections
>
> > How can I make a polygonal selection for example,
> > and make another selection inside of it, and fill or
> > clear the space between them?
>
> Hold down the alt key while making the second selection and it will  
> be subtracted from the first. You will then have a donut-shaped  
> compound selection that can be filled, cleared or measured.
>
> -wayne
>
>