提出一种基于基线和中心点的电场模型，用于估计指纹方向场．在靠近指纹基线区
域，方向场与基线平行，这是指纹基线作用的结果；中心点区域的方向场变化比较大，这是中心点作用的结果．基线区域和中心点区域的指纹方向场向外扩张，在三角点区域汇合，且三角点是最终的汇合点，这一模型能比较好地解释指纹中心点和三角点成对出现的原因．在NIST-4指纹库中进行了测试，试验结果表明电场模型生成的指纹方向场有较高的准确性．

An electric field model based on baseline and core points is proposed to estimate fingerprint orientation field. Orientation field firstly emerged in baseline and core area. Orientation field near baseline is parallel to baseline which is caused by baseline. Orientation field near core point is changeable which is influenced by core point. Then fingerprint orientation field outspreads. At last, orientation field converges at delta point. This model can explain well why core and delta points exist in pairs in fingerprint images. Experimental results in NIST-4 show that our model can estimate fingerprint orientation field fairly accurately.