Geometric Feature-based Edge-Matching

Edge-matching is one of the most useful procedures in processing spatial data. But several frequently used methods have showed their shortcomings. They are blind to error data included in the original data, and most of them are sensitive to a threshold. An effective matching procedure should correct most of the errors included in the data, or should detect these errors which may not be easily corrected. Aside from this, all lines are matched successfully. Geometric feature-based edge-matching procedure is one such method which is applied to match contour line data from photogrammetric model. Because every type of geographical element has innate geometric features represented by the geometric data (coordinates). These data processed should demonstrate their geometric features. By comparing the geometric features of the data with the innate ones, we know which links are the best ones. So the geometric features of elements may be regarded as credible data in the process. A procedure matching contour line with the test of its features can be converted to a search procedure. It is depth-optimised. The procedure looks for a correct path on a reversed "tree" and its nodes are the contour segments. Correct path gives out the sequence of linking these segments.