A signal processing apparatus for performing a filtering process on an input image using a plurality of filters to generate an output image includes the following elements. A region variance value calculating unit calculates a region variance value for a region around a predetermined pixel used as a pixel of interest on the input image. A filter processing unit applies a filtering process to a pixel value of the pixel of interest using the filters. A reflection amount determining unit determines a reflection amount based on the region variance value. A combining unit calculates a pixel value of a pixel of the output image corresponding to the pixel of interest on the basis of respective filter output values obtained by filtering processes applied by a plurality of filter processing units, respective reflection amounts determined with respect to the filter output values, and the pixel value of the pixel of interest.