This paper presents an enhanced method of slit beam projection intended for the rapid measurement of 3-dimensional surface profiles of dies and molds. The finite element camera calibration method based on the two-plane camera calibration is newly suggested. In addition, precise and easy implementation techniques for the camera calibration method are presented. Special emphasis is given to optimizing the design of optical system so that the measuring accuracy can be maximized in a given measuring range. And, sub-pixel image processing techniques using polynomial curve fitting are implemented. Finally, several measurement examples are discussed to demonstrate that an actual measuring accuracy of ±0.1mm can be achieved over the measuring range of 500mm×300mm×200mm.
