An efficient algorithm is proposed for the interpolation of interlaced images. On the basis of the edge-based line average (ELA) algorithm, tow useful measurements are introduced within the operation window in order to alleviate misleading decisions in determining the direction where the interpolation is to be made. By efficiently estimating the directional spatial correlations of neighboring pixels, increased interpolation accuracy has been achieved. In addition, the new method is simply structured and is therefore easy to implement. Extensive simulations conducted for different images and video sequences have shown the efficacy of the proposed interpolator, with significant improvement over previous ELA-based algorithms.