The present work aims to analyze and characterize the macro-geometrical defects of surfaces.
As a way of characterization an optical method is used, which is the projection of fringes that is a technique of non-destructive measurement.
The location, depth and size of surface defects can be determined automatically by projection of four figures of rectilinear fringes shifted in phase on the surface to be tested. An optical mounting of triangulation to project the fringes is then performed.
After projection, the projected gratings images are captured by a CCD camera, digitized and stored in computer memory. The application of phase shifting algorithm with four steps is achieved to determine the initial phase that contains the "measurand", which is the difference in shape. Pieces with different forms were tested.