有限差分法编写的三维迭代偏移代码，算法精度高。-Finite difference code written in three-dimensional iterative shift algorithm and high accuracy.

阈值分割分各种算法，如基于灰度直方图的阈值分割，迭代阈值分割，最大类间方差阈值分割法，局部阈值法等。-Thresholding of various algorithms, such as histogram-based thresholding, iterative threshold segmentation, Otsu threshold segmentation method, local threshold method.