Efficient digitizing of sculptured surfaces using wavelet transform

Abstract

Surface digitization is an approach to obtain three-dimensional measurement of an unknown sculptured surface. The quality and the efficiency of surface digitization are two main concerns which have drawn much attention in the manufacturing industries. A cost-effective digitizing approach can not only reduce the measuring time, but also improve the accuracy of measurement. In the past, the digitizing methods were performed in such a way that the digitizing points were chosen at intervals with a constant distance. However, many local areas of a sculptured surface can be well-represented by fewer points. Therefore dense digitizing of conventional digitizing schemes is not efficient. In this paper, a new irregular digitizing scheme based on the wavelet transform is proposed. First an initial depth map of sculptured surface is obtained by using computer vision. From the initial depth map, the wavelet transform is used to select the necessary digitizing points for further digitization by highly accurate measuring equipment. Once the digitizing points are re-measured, the surface can be reconstructed by wavelet synthesis technique.