  We present a detailed study of a filtering method based upon Dirac
quasi-zero-modes in the adjoint representation. The procedure induces no
distortions on configurations which are solutions of the euclidean classical
equations of motion. On the other hand, it is very effective in reducing the
short-wavelength stochastic noise present in Monte Carlo generated
configurations. After testing the performance of the method in various
situations, we apply it successfully to study the effect of Monte Carlo
dynamics on topological structures like instantons.
