The invention provides an image interpolating method, which comprises receiving the low resolution pixels Y.sub.ij. Then, a homogenous area and an edge area of the image are determined according to pixel differences of the pixels Y.sub.2i,2j in comparing with a threshold. Then, the pixels Y.sub.2i,2j belonging to the homogenous area are interpolated by a first interpolating algorithm, while the pixels Y.sub.2i,2j belonging to the edge area are interpolated by a second interpolating algorithm.