1. An apparatus for image interpolation comprising: an edge direction detector detecting an edge direction for a pixel nearest to a to-be-interpolated pixel among pixels and determining the edge direction of the to-be-interpolated pixel as the detected edge direction, the pixels having determined pixel values in an image frame; a pixel value calculator calculating pixel values of interpolation points located in a lattice filtering window having a predetermined size by using pixel values of pixels located adjacent to the interpolation points, the lattice filtering window having the to-be-interpolated pixel at the center therein; and a filtering unit performing low pass filtering on the to-be-located pixel according to a low pass filter corresponding to the determined edge direction of the to-be-interpolated pixel, the low pass filter being one of low pass filters corresponding to predetermined vertical, horizontal, left diagonal and right diagonal directions respectively.