A FRINGE CENTER DETECTION TECHNIQUE BASED ON A SUB-PIXEL RESOLUTION, AND ITS APPLICATIONS USING SINUSOIDAL GRATINGS

A common problem in optical profilometry is the accuracy in locating f ringe centers. This paper presents an accurate fringe center detection technique based on sub-pixel resolution using the fringe projection m ethod. An optimum reconstruction filter is developed which has low sen sitivity to noise. In fringe center detection, computer simulation res ults of using one-pixel and sub-pixel resolutions are compared. The de tection technique is then applied to radius measurement of cylindrical objects and surface profile measurement of diffuse objects. The exper imental results thus obtained through the proposed optimum reconstruct ion filter show significant improvement in measurement accuracy.