Re: Questions about analysis "radial intensity distribution"

Posted by Martin du Saire on
URL: http://imagej.273.s1.nabble.com/Image-transform-tp3703413p3703416.html

If I have understood correctly,  you need to get
the profiles along each radius "by hand".  For example:

for (j=0; j<nAngles; j++) {
       makeLine(fX,fY,fX+(profileRadius*cosA[j]),fY+(profileRadius*sinA[j]));
//    (fX, fY) are the coordinates of the center
of the object or region you want to profile
//    cosA and sinA are lookup tables, or you could calculate them on the fly
       profile = getProfile();
//    profile now contains the intensities along
the selected direction for you to use as needed
}

M


At 11:03 AM 3/6/2006, you wrote:

>Dear Liu:
>   I don't know if this could be of help, but
> there is a plug-in called "radial profile" which maybe could help you.
>
>   fjam
>
>"Liu, Dongfang (NIH/NIAID) [E]" <[hidden email]> escribió:
>   Dear friends,
>I am new user of Image J.
>I am sorry to bother you.
>I am looking for your help about the analysis of
>"radial intensity distribution" . The radial
>intensity distribution I(r) of the flourescence
>dot was fit for each frame with a nonlinear
>Levenberg-Marquardt routine to the
>Gaussian:I(r)=Io exp(-R^2/w^2) +BG, where R is
>the distance of each pixel to the center of
>mass. The fitting parameters are Io, w, and BG,
>where Io is the peak intensity, BG is the
>background intensity, and w is the measure of
>the width (the Gauss width). It is very
>important for us to get the peak intensity and
>width. some people suggest me to use Plot Profile(Analyze -> Plot.
>But I think the "plot profile" is not good.
>Because the concept of "plot profile"---Displays
>a two-dimensional graph of the intensities of
>pixels along a line within the image. The x-axis
>represents distance along the line and the
>y-axis is the pixel intensity. For rectangular
>selections, displays a "column average plot",
>where the x-axis represents the horizontal
>distance through the selection and the y-axis
>the vertically averaged pixel intensity
>I was confused that how to calculate the "radial
>intensity distribution" in Image Pro Plus or
>Image J or other software. Could you help me?
>Advice would be greatly appreciated.
>I am looking forward to your reply.
>
>Thank you very much.
>Best regards
>df
>
>
> > ----------
> > From: Gabriel Landini
> > Reply To: List IMAGEJ
> > Sent: Friday, March 3, 2006 12:10 PM
> > To: List IMAGEJ
> > Subject: Re: Image transform
> >
> > On Friday 03 March 2006 16:25, Liu, Dongfang (NIH/NIAID) [E] wrote:
> > > Thank you for your help.
> > > Yes, the system is a miroscope. Could you tell what other optics I should
> > > consider to calibrate a image?
> >
> > No, I couldn't because I do not know what
> kind of optics your microscope has.
> >
> > You have to do this:
> >
> > > > You need to put a known
> > > > sized object under your imaging system
> and see how many pixels it spans.
> > > > Then you estimate the size of your pixels
> dividing the known size of your
> > > > object by the number of pixels it occupies.
> >
> > Cheers,
> >
> > Gabriel
> >
> >
>
>
>
>---------------------------------
>
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