I am trying to extract harmonic motion from series of images. One approach ist to simply take the (discrete) fft:
tmp = fft(imageSeries, , 3);
where imageSeries is a stack of black and white images with the third dimension being the image number. I can then select the bin I expect my motion in (the 3rd bin as it happens) and extract my result.
The other option is to compute the optical flow between consecutive images and extract the harmonic motion again using the third bin of the fft.
As I am very unfamiliar with signal processing, I'm now unsure what the units in my (now complex) motion fields should be. I know that the optical flow algorithm should return in units of pixels per step, but what happens when I use the fourier transform on this? And what units do I get when I simply fouriertransfrom along the stack? Any explanation or resources are very appreciated, thank you for your time