Re: X-Y coordinates to pixels

Posted by Michael Cammer on
URL: http://imagej.273.s1.nabble.com/X-Y-coordinates-to-pixels-tp3703825p3703827.html

To measure particles, either you need to do it per pixel which, by
definition, is a discrete number, or you need to look at a block of pixels
and do a gaussian or other fit if you need to find a fraction of a pixel
location.
-mc



At 09:14 AM 02/02/06 -0500, you wrote:

>Dear Sir,
>
>I have the same problem. Could I calculate the displacement of two
>particles according to the pixel size?
>
>
>
>
>
>
>
>**********************************************
>Dongfang Liu
>Laboratory of Immunogenetics
>National Institute of Allergy and Infectious Disease
>National Institute of Health
>Twinbrook II, Room 207
>12441 Parklawn Drive
>Rockville, MD 20852
>Phone: [phone]
>Fax:[phone]
>email:[hidden email]
>**********************************************
>
> > ----------
> > From:         Curtis Rueden
> > Reply To:     List IMAGEJ
> > Sent:         Wednesday, February 1, 2006 3:20 PM
> > To:   List IMAGEJ
> > Subject:      Re: X-Y coordinates to pixels
> >
> > Hi Leslie,
> >
> > I do not know if there is a way to measure points at higher precision in
> > ImageJ (though I would be surprised if there is not), but this is one of
> > the things VisBio (http://www.loci.wisc.edu/visbio/) can do. You can
> > place markers in double-precision floating point, and then export them
> > to a text file for use in a spreadsheet. See the Overlays page in the
> > "Data Transforms" section of the program's built-in help for details.
> >
> > -Curtis
> >
> > Leslie Day wrote:
> >
> > >I am hoping someone could help me. I am trying to map a point as it moves
> > >through a series of images in order to find out velocity of the object and
> > >distance traveled.. I figured the best way would be to keep creating
> points
> > >with the point selector and then map the points. However, currently when I
> > >use the point selector it gives me x-y coordinates in whole numbers. I
> need
> > >something with more significant figures (3 decimal spots) to be able
> to see
> > >the movement. Maybe in pixels or ?m. Perhaps there is another way to
> detect
> > >linear velocity and distance traveled through a series of images.
> > >
> > >
> > >
> > >Thanks
> > >
> > >
> > >
> > >Leslie Day
> > >
> > >Biology Department
> > >
> > >Northeastern University
> > >
> > >[hidden email]
> > >
> > >617-373-3780
> > >
> > >
> >

____________________________________________________________________________
Michael Cammer   Analytical Imaging Facility   Albert Einstein Coll. of Med.
Jack & Pearl Resnick Campus      1300 Morris Park Ave.     Bronx, NY  10461
[phone]       Fax:  [phone]      URL:  http://www.aecom.yu.edu/aif/
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