Abstract: An improving sketch-based interfaces algorithm is provided.The user interactively sketches a set of strokes with a curve in mind，this algorithm analyzes multiple strokes and replaces them with a single stroke that makes a reasonable estimate of the designer’s intention.Space is subdivided recursively and stopped where either there is only a single stroke，or several strokes that have a proper ordering using Principal Component Analysis（PCA）.The subspaces are then reconnected，and a large list of points is formed.The resulting curve is very noisy due to the multitude of strokes.A control points creating technique that makes use of reverse subdivision is used to fit a smooth B-spline curve.

Key words: 2D curve, multiple strokes, B-spline

摘要： 提出一种改进基于手绘的界面的算法。该算法通过分析多重笔画，并用单一笔画取代多重笔画，以求合理地解释设计者的创作意图。递归地细分空间，直到只剩一个笔画或者用主成分分析方法处理后实现合适的顺序;被细分的空间被重新连接，同时产生一个巨大的点的列表;因为曲线非常嘈杂，该算法利用反向细分求控制点来拟合出一条光滑的B样条曲线。

关键词: 二维曲线, 多笔画, B样条