Amplitude and Phase

Category: Data Processing and Evaluation – Images
Description: This script calculates the spatial frequency, amplitude, and phase of the peaks (i.e., bright spots) in the Fourier transform of an image,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 one or more bright spots. The Shift-key must be held down when making multiple selections. The script outputs the data in rows containing the spatial frequency, amplitude, and phase. The data is tab-delimited to facilitate pasting into Excel etc. The amplitudes and phases are calculated according to the equations in W.J. de Ruijter. Journal of Computer-Assisted Microscopy, 6(4):195-212, 1994.
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