Fleet, D.J. and Langley, K.
Computational analysis of non-fourier motion.
Vision Research 34(22):3057-3079, 1994
Non-Fourier motion is now commonplace in research on visual motion
perception, yet lacks a computational framework. This paper examines
this issue based on the observation that many non-Fourier motion stimuli
have a simple characterization in the frequency domain, in terms of
oriented power distributions that lie along lines (or planes) that do
not pass through the origin. This provides a unifying theoretical
framework for a very diverse class of non-Fourier phenomena. It also
allows us to examine some central issues concerning the computational
nature of non-Fourier models, and naturally occurring sources of
non-Fourier motion. For example, it is shown that the orientation of
power in frequency domain corresponds to the velocity of a multiplicative
envelope, and may arise as a restricted form of lighting effects,
translucency or occlusion. We also show that both the location and
orientation of spectral power may be extracted from the phase and
amplitude output of band-pass filters, consonant with existing
Return to David Fleet's home page.