Strip Image Processing In 3-D Profilometry Measurement Using Grating Projection

Grating Projection is a method that captures the 3-D surface profilometry of an object without any contact but high speed. Because of the cragginess of the 3-D surface, the distortion stripes appear when the common rectangular grating or sine grating is projected onto the object surface, which includes information about the 3-D surface profilometry. The images including distortion stripes are taken by CCD camera. The 2-D stripes information is got after processing these images. On the basis of mathematic reconstruction model and arithmetic, the 3-D surface profilometry data are gotten.In this paper, the chapter 1 make a survey of the 3-D shape measurement, shows the position that what I research lie in this area. In chapter 2, the basic process of grating projection are described simply . Then, the module of image processing are introduced, including the data structure and arithmetic of image filtering and image thresholding. The oriented-object technique are also described. Chapter 3 is mainly about the thining of image, some sutra arithmetic are described and compared. Then, we study the subpixel measurement techniques, and use curve fitting in image thining to improve the precision of the result. The chapter 4 studies how to code the grating pattern. Discriminating the order of the grating pattern is important in grating projection. The Gray Code method is introduced, and we present a method named border code method. We concluded in chapter 5.