In order to improve the real-time performance of particle filter, this paper proposes an efficient particle filter algorithm
and evaluates its usage in object contour tracking application. This new filter uses only one particle to predict next state
in certain situations. As particle set size is one, there is no need to resample the particles before prediction. Therefore the
real-time performance of particle filter is improved. To maintain the performance of particle filter, we use one particle
sample only in prediction step and only in situations where particles are close enough with each other. After prediction
step, the original number of particle samples is recovered. Experiment shows that the new particle filter uses less time to
process the particles while retain tracking performance comparable with the regular particle filter.