analysis of objects with holes

[luis amaral]

Hello.
I am trying to determine the number of pixels (or length) of the
skeleton of the objects within a given image. Some of the objects
however have holes inside leading to skeletons like a circle. When I try
to determine the area of these skeletons by the macro command
run("Analyze Particles...",…) this command always fill the holes within
the circle and determines the filled area. How can I prevent this? Or is
there another way to determine each skeleton individual length?
I would very much appreciate if someone could help me.
Luís Amaral
 
__________________________________________________________________
­­­­­­­­­­­­
António Luís Pereira do Amaral
Departamento de Tecnologia Química
Escola Superior de Tecnologia e de Gestão - Instituto Politécnico de
Bragança
Campus de Santa Apolónia, 5301-857 Bragança – Portugal
Tel.: [phone]
Tlm.: ([phone]
e-mail:  <mailto:[hidden email]> [hidden email];
<mailto:[hidden email]> [hidden email]
 <http://www.deb.uminho.pt/BioPSEg/lpamaral>
http://www.deb.uminho.pt/BioPSEg/lpamaral
 <http://dtq.estig.ipb.pt> http://dtq.estig.ipb.pt
__________________________________________________________________
 

[Gabriel Landini]

On Wednesday 14 September 2005 18:19, luis amaral wrote:
> Hello.
> I am trying to determine the number of pixels (or length) of the
> skeleton of the objects within a given image. Some of the objects
> however have holes inside leading to skeletons like a circle. When I try
> to determine the area of these skeletons by the macro command
> run("Analyze Particles...",…) this command always fill the holes within
> the circle and determines the filled area. How can I prevent this? Or is
> there another way to determine each skeleton individual length?
> I would very much appreciate if someone could help me.

My Particles8 plugin a part of the Morphology collection (link to my site at
IJ Plugins page) can count pixels in an object without filling the holes.
Cheers,

G.

[Wayne Rasband]

> I am trying to determine the number of pixels (or length) of
> the skeleton of the objects within a given image. Some of
> the objects however have holes inside leading to skeletons
> like a circle. When I try to determine the area of these
> skeletons by the macro command run("Analyze Particles...",…)
> this command always fill the holes within the circle and
> determines the filled area. How can I prevent this? Or is
> there another way to determine each skeleton individual
> length? I would very much appreciate if someone could help
> me.

There are two ways to get the particle analyzer to ignore interior
holes. You can threshold the image and check "Limit to Threshold" in
the Analyze>Set Measurements dialog, or check "Flood Fill" in the
particle analyzer dialog box.

-wayne