A technique of nonlinear filtration of signals is proposed, which allows one to smooth the regular inhomogeneities of the signal while amplifying signal drops due to anomalous inhomogeneities of a medium. The filtration made using this technique was compared (in numerical experiments) with the linear and median filtration. The comparison showed high efficiency of the proposed filtration technique. This has also been confirmed by the results of filtering the experimental data obtained in a turbid medium and in a medium with turbulent inhomogeneity.