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Re: Counting pixels above a certain grey value in a stack

Posted by Joel Sheffield on Jul 17, 2009; 1:21am
URL: http://imagej.273.s1.nabble.com/Counting-pixels-above-a-certain-grey-value-in-a-stack-tp3691747p3691752.html

I think that the problem is that you are trying to get a threshold for a
16-bit image.  As I understand it, that function works only with 8-bits.
--You might try changing the image type.  It looks as if you don't need the
16 bits of resolution --Joel

On Thu, Jul 16, 2009 at 5:43 PM, blarz15 <[hidden email]> wrote:

> Hi Jerome,
>
> Thank you for your helpful post.  I am trying to do what you suggested, but
> I'm having a hard time getting the threshold function to work properly.
> When I access the threshold menu, this is what I get:
>
> http://n2.nabble.com/file/n3269373/Picture%2B1.jpeg
>
> For some reason, I am not able to set the value range for my image.  Any
> advice would be much appreciated!
>
> Thanks,
>
> Barrett
>
>
>
>
> jerome mutterer-2 wrote:
> >
> > Hi.
> > I'm not sure a plugin is necessary in that case. Selecting pixel value
> > ranges is just exactly what the threshold does. I suggest the following
> > procedure :
> > * go to Image/Adjust/Threshold and set the value range you would like to
> > measure.
> > * go to Analyze/Set Measurements, and make sure you check the "limit to
> > threshold" checkbox and the "area" field.
> > * go to Image/Stacks/Plot Z-axis Profile
> > You're done.
> >
> > Jerome
> >
> >
> > On Dec 4, 2007 2:42 PM, Johannes Schindelin <[hidden email]>
> > wrote:
> >
> >> Hi,
> >>
> >> On Tue, 4 Dec 2007, Bio7 wrote:
> >>
> >> > public class Count_Stack_Pixels implements PlugIn {
> >>
> >> If you implement a PlugInFilter (which returns DOES_8G | DOES_16 |
> >> NO_CHANGES in setup()) you do not need to find out the current image
> >> or check the image type yourself.
> >>
> >> >                               /*We create a dialog!*/
> >> >                               GenericDialog gd = new
> >> GenericDialog("Count Pixels");
> >> >                               gd.addNumericField("Min: ", min, 0);
> >> >                               gd.addNumericField("Max: ", max, 0);
> >>
> >> You could reuse the min/max setting from the threshold.
> >>
> >> Ciao,
> >> Dscho
> >>
> >
> >
>
> --
> View this message in context:
> http://n2.nabble.com/Counting-pixels-above-a-certain-grey-value-in-a-stack-tp635323p3269373.html
> Sent from the ImageJ mailing list archive at Nabble.com.
>



--


Joel B. Sheffield, Ph.D
Department of Biology
Temple University
Philadelphia, PA 19122
Voice: 215 204 8839
e-mail: [hidden email]
URL:  http://astro.temple.edu/~jbs