曲面拟合法是一种高精度、计算量小、抗噪性能强的方法，当前已被广泛地应用于
各种场景。比如岩石材料的变形测量、电子器件变形的测量、基于掌纹图像相关匹
配的重复定位技术等。曲面拟合法能够成功计算出亚像素位移的前提是整像素搜索阶
段可以正确搜索出模板的整像素匹配点，一旦整像素匹配点搜索出现错误，那么亚像素
测量阶段所得到的位移距离就会失去意义。
使用不同的拟合函数对相关系数矩阵进行曲面拟合，会对结果产生一定的影响，比
较常用的拟合函数有二次函数、三次函数、高斯函数等。(Surface fitting method is a high-precision, computational complexity is small, strong anti-noise performance method, has been widely used in various scenes. For example, deformation measurement of rock materials, deformation measurement of electronic devices, and repetitive location technology based on palmprint image correlation matching. Surface fitting method can successfully calculate the sub-pixel displacement on the premise that the whole pixel search stage can correctly search the template of the whole pixel matching point, once the whole pixel matching point search error, then the sub-pixel measurement phase of the displacement distance will be meaningless.
Using different fitting functions to fit the surface of the correlation coefficient matrix will have a certain impact on the results. The commonly used fitting functions are quadratic function, cubic function, Gaussian function and so on.)