Measure FT

Category: Data Processing and Evaluation – Images
Description: This script can be used to measure the spatial frequency of the peaks (i.e., bright spots) in the Fourier transform of an image and also the central angle between the bright spots, using sub-pixel interpolation. For the script to work correctly, the original image must have been multiplied by a Hanning window before the FFT was calculated. Before running the script, use the rectangular selection tool to select two or more bright spots. The Shift-key must be held down when making multiple selections. The script outputs the data in rows containing the (central) angle and the spatial frequency of the two bright spots forming the angle. The data is tab-delimited to facilitate pasting into Excel etc. For more information on sub-pixel interpolation see W.J. de Ruijter et al. Ultramicroscopy, 57:409-422, 1995.
Comments: The spatial frequencies are given as unitless numbers and must be multiplied by a scale factor to give the actual value (e.g., in nm-1).
Script version: 1.0
DM/GMS version: 3.11
Script written as a function: No
Source: Show code
Download Source Code: Download
Download Zip File: Download