by using the statistic properties of the correlation coefficient, a curve correlation coefficient is calculated, and then the matching point is obtained through evaluating it's derivative function.
利用相关系数在真实匹配点附近的统计特性,通过对相关系数进行曲线拟合,根据其一阶导数确定最大相关系数所在的位置,快速得到亚像素匹配点。