Shape detection based on topographic extraction from the width of a light line

A simple, fast and accurate light line projection technique for direct dete ction of three-dimensional shape is presented by simulation and verified ex perimentally. To obtain the object surface shape, the object is moved along an axis by an electromechanical device and scanned by a light line. The pr ofilometric method is based on the principle that the height data of an obj ect can be obtained from the projected light line displacement. In this tec hnique, object topography is extracted by measuring the position of a set o f intensity points along of the projected vertical light line. This topogra phy is an object section, which corresponds to the width of the light line. The proposed way to obtain the topographic information has also ability to measure complicate and small details of an object. The light line computer processing by using the proposed method is very fast. This is due to the l ight line intensity is approximate to continuous function by Bezier curves method. This technique consists on taking a set of points from the Light li ne profile and fitting them to a smooth continuous curve. The displacement measurement of every intensity point along the vertical light line is obtai ned with a resolution of pixel fraction. With this resolution height data o f the object can be obtained with a higher accuracy of 0.001 mm.