Contour Extracting From Digital Bandshaped Light Image

The Structured Light Image Method (SLIM) is a kind of new way on non-touching sculptured surface measuring which develops in recent ten years, with clear principle and simple construction.First, all kinds of sculptured surface measuring methods are introduced in the paper. The paper expounds the basic principle of SLIM, analyzes the projective transformation between image and object, and the coordinates conversion between in computer display and in photosurface of CCD. After obtaining Structured Light Image (SLI), SLI is pretreated by region segmentation and 8 neighbor filtering .So the objective image is separated from background. In order to reduce data operand and memory capacitance in the objective region, the paper presents new method which parts and stores the region.Based on research of the fringe method, the midline method, the depth restrict method, and so on, the paper puts forwards new method of contourextracting--the Gray Barycenter Based on Edge (GBBE). Contour extractingis kernel problem of SLIM. The algorithm is explained in detail, based on classifying CCD image, the normal is obtained. The Gray Barycenter on the normal is contour point. A serial of contour points make up of contour curve. Contour data on light sectioning is attained by composition of contour curves.The paper also describes function and flow chart of modules which make up of software of the measuring system, introduces the mechanical device and the control system of the measuring system.Finally, the paper analyzes the measuring accuracy by experiment, it shows the measuring accuracy of the method meets requirement for the measuring system.