Surface orientation from a projected grid

✍ Scribed by Shrikhande, N.; Stockman, G.

• Book ID: 117873004
• Publisher: IEEE
• Year: 1989
• Tongue: English
• Weight: 665 KB
• Volume: 11
• Category: Article
• ISSN: 0162-8828
• DOI: 10.1109/34.24799

✦ Synopsis

Two simple methods are given for obtaining the surface shape of objects using a projected grid. After the camera is calibrated to the 3-D workspace, the only input data needed for the computation of surface normals are grid intersect points in a single 2-D image. The first method performs nonlinear computations based on the distortion of the lengths of the grid edges and does not require a full calibration matrix. The second method requires that a full parallel projection model of the imaging is available, which enables it to compute 3-D normals using simple linear computations. The linear method performed better overall in the experiments, but both methods produced normals within 4-8 degrees of known 3-D directions. These methods appear to be superior to methods based on shape-from-shading because the results are comparable, yet the equipment setup is simpler and the processing is not very sensitive to object reflectance.