A discrimination apparatus includes a separating unit configured to separate kinds (N being a natural number of 2 or greater) of color signals forming an image signal obtained by image acquisition of a subject with a color imaging system into kinds (M being a natural number of 1 or greater, M≦N) of wavelength ranges, based on known spectral characteristics of a subject to be discriminated, at least one of the separated wavelength ranges including a plurality of color signals. The discrimination apparatus further includes a noise estimating unit configured to estimate a noise amount in each predetermined unit area in each of the wavelength ranges separated by the separating unit, and a noise reducing unit configured to perform a noise reducing processing on each of the wavelength ranges separated by the separating unit, based on the noise amount estimated by the noise estimating unit. The discrimination apparatus further includes a discriminating unit configured to perform a discriminating processing on the subject to be discriminated, based on the color signals in the wavelength ranges noise-reduced by the noise reducing unit.