1. A method comprising: determining a lowest-score interpolation direction among a plurality of interpolation directions; calculating a candidate pixel value by interpolating along said lowest-score interpolation direction; and applying a median function to a set of pixel values that includes: (a) said candidate pixel value; (b) at least one pixel value from a line of pixels that is immediately above a pixel location that is currently being interpolated; and (c) at least one pixel value from a line of pixel values that is immediately below said pixel location that is currently being interpolated.