2.1 Segmentation threshold selection Chose the save path use【Save】 、Reference images【V0】and Current images【V1】file path (note: Currently only supports .tif format images, non-RGB3 layer data, preferably uint8 format, reducing memory requirements in big data). The threshold is selected to adjust the matching of the two CT data on Z, reducing the post-DVC calculation pressure and improving the accuracy. You can choose the segmentation threshold at the beginning, such as "0,1" (only this form, two values + one comma in the middle, and must be in English), enter【Try Thod】, Choose the appropriate threshold based on the most prominent and stable material in the results. As shown in the figure below, this material is a mixed soil containing clay and quartz particles, while quartz particles are relatively stable. According to the cross-sectional view of the above figure, it can be confirmed that the approximate gray value range of the quartz particles (not very accurate) is "120,200", and the following figure is obtained. The threshold range is continuously adjusted according to the comparison effect of Fig. subplot(2,3,2-3) and Fig. subplot(2,3, 5-6) until it is reasonable. until.