Fig. 1. Schematic of statistical filtering processing

Fig. 2. Schematic of radius filtering processing

Fig. 3. Optimization strategy mainly deals with technical processes

Fig. 4. Results of three buildings point clouds using the proposed filtering optimization strategy(statistical filtering and passthrough filtering).(a1)(a2)(a3) Original point clouds of the three buildings;(b1)(b2)(b3)results of statistical filtering ;(c1)(c2)(c3) results of passthrough filtering

Fig. 5. Results of three buildings point clouds using the proposed filtering optimization strategy(CSF and radius filtering).(a1)(a2)(a3)Results of CSF ;(b1)(b2)(b3)local enlarged images of CSF;(c1)(c2)(c3)results of radius filtering ;(d1)(d2)(d3)local enlarged images of radius filtering

Fig. 6. Test results of 1 # building point cloud with three different compression methods.(a1)Point cloud after filtering;(a2)(a3)local enlarged images corresponding to box 1 and 2 in Fig. (a1) ;(b1)result of curvature graded compression;(b2)(b3)local enlarged images corresponding to box 1 and 2 in Fig. (b1);(c1)result are compressed by the Geomagic studio software;(c2)(c3)local enlarged images corresponding to box 1 and 2 in Fig. (c1);(d1)result of center point nearest point mesh compression;(d2)(d3)lo

Fig. 7. Test results of 2 # building point cloud with three different compression methods.(a1)Point cloud after filtering;(a2)(a3)local enlarged images corresponding to box 1 and 2 in Fig. (a1);(b1)result of curvature graded compression;(b2)(b3)local enlarged images corresponding to box 1 and 2 in Fig. (b1);(c1)result are compressed by the Geomagic studio software;(c2)(c3)local enlarged images corresponding to box 1 and 2 in Fig. (c1);(d1)result of center point nearest point mesh compression;(d2)(d3)loc

Fig. 8. Test results of 3 # building point cloud with three different compression methods.(a1)Point cloud after filtering;(a2)(a3)local enlarged images corresponding to box 1 and 2 in Fig. (a1);(b1)result of curvature graded compression;(b2)(b3)local enlarged images corresponding to box 1 and 2 in Fig. (b1);(c1)result are compressed by the Geomagic studio software;(c2)(c3)local enlarged images corresponding to box 1 and 2 in Fig. (c1);(d1)result of center point nearest point mesh compression;(d2)(d3)loc

Table 1. Changes in the number of point clouds in each program

Table 2. Comparison of entropy changes of different compression methods