在很多应用领域，要求图像配准的精度达到亚像素级。对现有的亚像素级图像配准算法进行了分类，介绍了几种最主要的亚像素级精度的配准方法，包括基于插值的方法、扩展的相位相关法、解最优化问题法，并对这些算法的思路、性能特点和最新进展进行了综述。然后从几个评价标准对各种算法进行了比较，分析了各自影响性能的因素和性能提升的空间。最后对未来的发展趋势进行了展望。

Sub pixel image registration is required in many applications. In this paper, firstly recent sub pixel registration algorithms as well as classical algorithms are classified into three categories: interpolation based method, extension of phase correlation and method that formulates the problem as an optimization problem. Basic theories, performance characteristics, and recent improvements of the three methods are presented in detail. Secondly, the reviewed methods are evaluated in some criterions, factors affecting performance are analyzed. And lastly future development is discussed.