1. A method for locating face landmarks in an input image comprising the steps of: (a) locating a face region in the input image by means of skin color; (b) finding, from the face region, a plurality of feature regions having different colors from the skin color, so as to align the input image according to the feature regions thereby obtaining an aligned input image; (c) comparing the aligned input image with a reference image located with face landmarks by performing a plurality of comparisons between pixel rows R i (i&equals;1, 2, 3,..., m) of the reference image and pixel rows T u (u&equals;1, 2, 3,..., p) of the aligned input image for obtaining m x p distances d(R i, T u ); and (d) in a first matrix formed of nodes (i,u) (i&equals;1, 2, 3,..., m; and u&equals;1, 2, 3,..., p), associating each node (i,u) with one of the distances d(R i, T u ), and in a path from a starting point (1, 1) to an ending point (p, m) of the first matrix, finding a minimum accumulated value of the distances d(R i, T u ) as a first optimal path, so as to obtain a correspondence between all pixel rows R i of the reference image and all pixel rows T u of the input image, thereby using the correspondence and the face landmarks of the reference image to find face landmarks of the aligned input image.