This paper proposes an optimization scheme for the image interpolation algorithms, in particular the bilinear algorithm. The only original point is a decision step in which it is decided whether the four neighbouring pixels have the same value and if so the conventional bilinear interpolation is replaced by a nearest neighbour interpolation. The experimental results corroborated the efficiency of the proposed scheme over conventional bilinear and showed improvements in terms of speed and quality, especially in case where images with less grain textures have been interpolated.