Posted by
Frederic V. Hessman on
Oct 23, 2007; 4:23pm
URL: http://imagej.273.s1.nabble.com/FFT-along-line-in-image-tp3698130p3698139.html
On the contrary, this has everything to do with "image processing":
there is no reason why "images" have to be 2-D and probably the
greatest weakness of ImageJ (don't get me wrong - I think it's
great!) is the inability to assign different scales and meaning to
different axes of arbritrary dimension. Yes, there are plugins, but
this needs to be at the heart of the ImageJ data model.
A sonogram (x=frequency, y=time) is usually displayed as an image.
Rick
On 23 Oct 2007, at 5:10 pm, Gluender wrote:
> Dear Jon Harman,
>
> what you are looking for is the 1D Fourier Transformation which has
> no direct relation to image processing. Consequently, you may have
> a look at general signal rpocessing software. You will find a lot
> of free 1D FFT code in the internet. I sometimes use a macro that
> comes with Kaleidagraph that in turn can be use in a demo mode for
> free (Mac & Windows versions available).
>
>> Hi,
>>
>> Is there a plugin to ImageJ that can calculate the FFT along a
>> line in the image and display the result (say for instance plot
>> the power spectrum)?
>>
>> Jon
>
> I suggest to export the line data etc.
>
> If precision and computational effort is not an issue you may even
> apply a 2D FFT to the line (set the rest of the image to zero) and
> you will get the Fourier spectrum of this line projected in one
> dimension.
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Dr. Frederic V. Hessman
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