The invention discloses a resolution converting method. Particularly, it discloses a resolution converting method having the steps of: inputting reference pixel data as pixel data which can be used for calculation of the pixel data of an interpolation pixel; and calculating the pixel data of the interpolation pixel by using a plurality of selected reference pixel data, wherein the selected plurality of reference pixel data include the reference pixel data which is selected in accordance with information corresponding to a position of the interpolation pixel in an area formed by mutually connecting positions of a plurality of adjacent pixels serving as a plurality of pixels adjacent to the interpolation pixel where the interpolation pixel is located.