Line Simplification Method Based on Multi-bends Groups Division

Line simplification is a classic issue and an important content in cartographic generalization. Based on the analysis of composing characteristics and the simplification process of linear features, a new simplification method was proposed to overcome the shortcomings of continuous bends selection method in general researches. First, based on bends visibility at the simplified scale, the linear feature was divided into several multi-bends groups which were composed of several series of invisible bends. Second, in order to avoid excessive simplification, several reasonable options of bends selection in each multi-bends group were generated from a proposed model. To minimize displacement resulting from simplification, the best option with the smallest area to be deleted of all selection options was chosen to simplify the relevant multi-bends group. Third, circular simplification would not be over until the simplified linear feature did not contain any invisible bends at the simplified scale. It was adopted to achieve a fully simplified result. Finally, the validity and the adaptability of the proposed method were verified with the qualitative and quantitative analysis by comparing different experimental results.