Triangulation method with stripe line of structured light is one of the most popular methods for extracting 3-D information. With this technique resolution of distance information is related to the translation of reflected light from the subject’s surface Because of changing in profile of the laser line on surface, we can not use mean, median or maximum intensity for thinning of laser line or we have to accept noticeable error on image processing steps. So we introduce a new method of thinning based on the Fuzzy rule