A discrete space-variant subwave-length dielectric grating (DSG) was used to develop a method for real-time polarization measurement. DSG are condidered wave plates with constant retardation and space-variant fast axes. This grating was formed by discrete orientation of the local subwavelength grooves. The complete polarization analysis of the incident beam was determined by spatial Fourier transform of the near-field intensity distribution transmitted through DSG followed by a subwave-length metal polarizer. A method for the formation of a complete depolarizer based on a polarization-state scrambling procedure over the space domain was also demonstrated.