Abstract: Vector map simplification plays an important role in the research on terrain simulation, cartographic generalization, and so on. As it is difficult to balance the overall shape and local feature point accuracy of the simplified curve with the existing algorithms, a vector map simplification method based on progressive iterative approximation (PIA) with B-spline curve was proposed. First, select the feature point sequence that can maintain the contour of the curve with the largest amount of information, and use it as the initial control point sequence to obtain the corresponding nonuniform cubic B-spline curve. Secondly, it obtained a series of curves that were gradually fitting the real one by iteratively adjusting the control points according to the bias between the fitted curve and the feature points until the accuracy requirements were met. The experiments result show that the PIA method can not only keep the overall geometry of the map curve, but also achieve high-precision approximation at feature points while meeting the global bias requirements. 

Key words: map synthesis, curve, spline, progressive-iterative approximation, simplification