Re: Saving and reloading FFT

Posted by Rasband, Wayne (NIH/NIMH) [E] on Sep 23, 2014; 12:46am
URL: http://imagej.273.s1.nabble.com/Saving-and-reloading-FFT-tp5009594p5009718.html

On Sep 22, 2014, at 8:12 PM, Divakar Ramachandran wrote:

> On Friday 12 September 2014 02:35 AM, Zack Gainsforth wrote:
>> Hi All,
>>
>> When I take an FFT of an image, it is obviously using reciprocal space coordinates.  However, if I save that FFT to a tif and then reload it later, it loses the reciprocal space and reports the units incorrectly as direct space.  Is there a way to set an image back into reciprocal space?  I tried, for example, Analyze->Set Scale... Unit of length = nm/c, or changing the distance in pixels from 17.6 to 1/17.6.  Better yet, it should retain that info when I save the image.
>>
>> Any ideas?
> I have been eagerly awaiting a response to this. A few years ago I had
> asked a related question about how electron diffraction patterns could
> be scaled in reciprocal units. The response at that time was that it was
> required to set a property, that was not accessible through the macro
> language. Is there a solution now? If the info could be retained when
> saved as TIFF, it would help a lot.

What version of ImageJ are you using? With version 1.48g and later, File>Save As>Tiff and File>Save As>ZIP save the FFT data of FFT windows, except for FFTs of RGB images.

-wayne
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