一种改进的数字图像亚像素位移测量算法

在三次曲面拟合法的基础上,提出了一种改进的亚像素位移求解算法。针对该算法中影响亚像素位移定位精度的两个因素进行分析,找出了最佳的拟合距离及合适的计算窗口子区。并用计算机生成的模拟散斑图,对该算法与常规的三次曲面拟合法针对计算精度、抗噪性能及效率进行了比较。试验结果表明,该算法相比一般的三次曲面拟合法,在计算时间增加较少的基础上,计算误差与抗噪性在一定范围内得到明显的改善。

An improved algorithm of digital image subpixel displacement measurement

An improved sub-pixel registration algorithm is proposed based on cubic surface fitting method.Two factors of the algorithm with measurement accuracy of sub-pixel dis-placement are analyzed and it is found out the optimal fitting distance and proper subsets of calculation window.Contrast tests have been made between the algorithm and the conven-tional cubic surface fitting in terms of registration accuracy and computational efficiency u-sing computer-simulated speckle images.The experiment result indicates that the algorithm relatively to the general cubic surface fitting has a slight increase in computing time and sig-nificant improvement in calculation error that an order of magnitude of registration accuracy has been improved.