We present the frequency domain analysis of the most general model of plana
r rigid motion, i.e., motion under the joint effects of translations and ro
tations with polynomial-type time dependence. We show that in the frequency
domain the contribution of the object's shape and texture is separate from
that of the motion parameters in this general framework. Special attention
is devoted to the case of translations and rotations with constant velocit
y and constant acceleration, which are the most likely candidates for model
ing motion in practical contexts. This work also focuses on the distinction
between the effects of the motion parameters and those of time duration, a
distinction that is necessary for a clear assessment of the effects of acc
eleration in the frequency domain. The results presented belong to the fiel
d of signal theory and may serve as a theoretical basis in the various appl
ications of motion models in the frequency domain, which include pattern re
cognition, television, image registration, image sequence analysis, and cla
ssification and neural modeling of motion perception. (C) 1999 Optical Soci
ety of America [S0740-3232(99)00606-7].