Calibration and topographic and profilometric methods using the prism normal measurement

摘要

The presented paper is dealt with the calibration of methods of the optical 3D measurement of the shape of objects. Methods can be divided into the two groups: topographic and profilometric methods. The topography is a method giving a contour map as result. On the other hand, the result of the profilometry is the data file containing the topographic depth (z-axis value) in the regular or irregular network of points (they are given by the x-axis and y-axis values). Every method needs the calibration of these values that means the relation between measured and resulting quantity. The x-axis and y-axis values are obtained as pixel distances from the record of optical image by the CCD camera. The z-values are computed by various ways in dependence of the calibrated method character. It can be the fringe orders, pixel distances again, phase differences or others. The paper describes the procedure of determination of calibration constants. It is based on the known object measurement by the calibrated method and the following evaluation of results.