为了更简单、有效地进行平面曲线的识别,首次给出了一种新的NRLCTI码的定义,并设计了一种新的算法用来匹配目标和模型轮廓曲线上的每段子曲线,同时还提出了一种从单幅图形和图像来识别平面曲线的方法。该识别方法首先利用NRLCTI码初步匹配了目标和模型轮廓曲线上的关键特征点,从而解决了用穷尽搜索法寻求特征点所对应的高费率和低效率的问题;然后在NRLCTI码匹配的前提下,再通过匹配目标和模型轮廓曲线上的每小段,从而解决了用多边形或圆锥曲线来近似曲线的不准确性问题。实验结果表明,该算法简单、有效。
In this paper, the definition of NRLCTI ( normalized run length code of conner and tangent and inflexion points) of a planar curve is given firstly. Then a new algorithm is designed to match sub-curves. Last, a novel approach is presented to recognize curves from a line drawing or an image. The proposed method has two merits. One is that the method matches feature points both on an object and models preliminarily based on NRLCTI, which can cope with the low efficiencyand high cost problem for reaching feature points corresponding. The other is that the method partitions the curve into many sub-curves based on the landmarks, then matches and recognizes them. The low accuracy for curve approximated by polygon or conics curve can be overcome. Computer simulations demonstrate the effectiveness of the algorithm preliminarily.