Abstract: Extracting the center of a light stripe is one of the key techniques of the linear structured light for threedimensional (3D) visual measurement. According to the influence of the accuracy in extracting the light stripe centers, the four key factors, which are the work environment, laser planes, measured objects and image acquisition systems, are summed up and analyzed. On the basis of the differences between the use of the image information and the characteristics of the calculated algorithms in the extraction methods, a new idea is proposed that they are classified into two different methods, which are the geometrical center method and the energy center method. Based on the differences between the two methods in algorithm thoughts, merits and demerits, ways of improvement, applicable conditions, they are subclassified, compared, analyzed and summarized. At last, with the developing features of the two methods combined, it proposes the development trend of the light stripe extraction method.

Key words: 3D visual measurement； linear structured light； light stripe； extracting the center