Abstract: In the searching of ASM algorithm for target points,only surrounding local gray-level information of pixel points in the profile neighborhood on the training images is adopted,and the pixel points are equally treated．Furthermore,searching space is only limited to several pixel points along the normal direction on both sides of fixed point of target image．Obviously,the searching space is too simple．Considering that color facial images are easily obtained and have rich information,the paper suggested that firstly the images are processed on three channels of R,G and B,and secondly pixel points in the profile neighborhood are endowed with different weights on the construction of local gray-level model．Thirdly,searching space is extended to pixel points on traditional normal line and other two adjacent parallel normal lines．The results of experiments show that the new algorithm greatly improves the accuracy of positioning by sixteen point five percent than traditional algorithm,so the improving way is feasible.

Key words: Active shape model (ASM),Local gray-level model,Facial feature points positioning,RGB space