Fig. 1. Cloth simulation filtering algorithm principle

Fig. 2. CSF algorithm error principle. (a) Steep slope error; (b) elevation correction error

Fig. 3. Algorithm process chart

Fig. 4. Full point cloud rendering

Fig. 5. The original point cloud maps of the survey area. (a) Test area 1; (b) teat area 2

Fig. 6. Schematic diagrams of the experimental area. (a) Test area 1; (b) test area 2

Fig. 7. Model diagrams of the experimental area. (a) Model of test area 1; (b) model of test area 2

Fig. 8. The results of the proposed algorithm, fabric simulation filtering algorithm, and local slope filtering algorithm. (a) The filtering results of the proposed algorithm in test area 1; (b) the filtering results of the proposed algorithm in test area 2; (c) the filtering results of CSF method in test area 1; (d) the filtering results of CSF in test area 2; (e) the filtering result of local slope filtering in test area 1; (f) the filtering results of local slope filtering in test area 2

Fig. 9. Comparison of the average accuracy of the two algorithms

Fig. 10. Comparison results of the proposed algorithm and the CSF algorithm on the ISPRS public dataset

Table 1. The accuracy of the proposed algorithm, classical CSF algorithm, and partially slope based filtering algorithm

Table 2. Comparison results of the proposed algorithm and the CSF algorithm on the ISPRS public dataset