Subpixel-precise Edge Extraction Algorithm Based on Facet Model

In order to quickly and effectively detect the templet profile, an edge extraction method based on Facet model is put forward. This method is to use the improved Canny algorithm for coarse positioning to extract the single-pixel -precise contour, and then use the 2D Facet model for fine positioning to extract the subpixel-precise contour. As a result, the problem of low efficiency and low localization is fundamentally solved for the Facet model to extract edge. Experiments prove this method can be effectively used to extract the subpixel-precise two-dimension outline. If images are taken with the industry video camera of high resolution power, it can detect the precision templet instead of three-coordinate measuring machine.