:A color coded projection grating is used to provide means of measuring 3 D surface profiles.Using white,red,green and blue stripes,we code the grating based on the binary system.Without losing generality,we use white and green stripes to represent 1 and 0 of high place and use red and blue stripes to represent 1 and 0 of low place in the binary system respectively.In the same time,we insert a black strip between two color stripes.This can not only prevent the blending between two color stripes but also double the space period of grating.So there are 16 strips in one period.So it is suitable for the 3 D measurement of human face.Since the strips are without gray scale levels,the measurement system possesses high ability of disturbance resistance.