Three-dimensional range data interpolation using B-spline surface fitting

Many optical range sensors use an equal angle increment (EAI) sampling. Such an EAI model generates data for surface geometrical description that have to be converted, in many applications, into data which meet the desired equal distance increment orthographic projection model. In three-dimensional (3D) image processing, a 3D interpolation scheme is needed to resample the range data into spatially equal-distance sampling data. In this paper, a resampling approach using a B-spline surface fitting approach is proposed. The first step is to select a new scale for all X, Y, and Z directions. The size of the new range image and the new coordinates of each point are then computed according to the actual references of (x,y,z) coordinates and the new scale. The new range data are interpolated using a B-spline surface fitting approach. The experiments show that this 3D interpolation approach provides a geometrically accurate solution for many industrial applications which deploy the EAI sampling sensors. (C) 2001 SPIE and IS&T.