A method and apparatus is disclosed for obtaining interpolation filters for use in a method or apparatus for enhancing the spatial resolution of a digital image. In the method or apparatus for enhancing the spatial resolution, input pixels from a low resolution image are classified and interpolated using the interpolation filters to form a high resolution image. The method for obtaining the interpolation filters includes obtaining a low resolution image from a high resolution source image. A plurality of pixels in the low resolution image are classified with respect to interpolation filters so that each of the plurality of pixels in the low resolution image is allocated to a respective interpolation filter. The interpolation filters are updated. The classifying and updating steps are repeated until a convergence criterion is met.