fft data matrix

[BlackEdition]

i was wondering if anyone knew how to extract the data matrix from the fft generated by imagej?  i would like to get the r, theta and intensity values for each pixel.

thanks!

[Michael Schmid]

Hi,

in the FFT options, you can select "Raw Power Spectrum"; this makes  
ImageJ create the 'PS' image where you have to do the measurements.  
Pixel values in this image are the (absolute) square of the FFT.

frequency=0 corresponds to x0=size/2, y0=size/2.

The frequency is image_size*pixel_size/distance_from_x0_y0
The angle is atan2(y-y0, x-x0).

Michael
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On 9 Jun 2009, at 01:16, BlackEdition wrote:


> i was wondering if anyone knew how to extract the data matrix from  
> the fft
> generated by imagej?  i would like to get the r, theta and  
> intensity values
> for each pixel.
>
> thanks!
>