Abstract
Abstract The shape-from-focus is an economic approach for 3-D measurement. However, the 3-D image reconstructed using this approach generally suffered by relatively high level of noise. In this study, it is of interest to optimize this technique to reach a better result. Modified-Laplacian (ML) operator and Sum-Modified-Laplacian (SML) operator are generally used in this approach to identify object in focus. The study confirmed that the use of SML after ML operator provide a more accurate result. However, using Gaussian filter between ML and SML operator is helpful in removing background noise. Adopting the median method can smooth the contour points and provide a more accurate result. Key word：Shape-from-focus, Optimization.