Author Affiliations
1 College of Surveying and Geo-Informatics, Tongji University, Shanghai 200092, China2 Key Laboratory of Advanced Engineering Surveying of NASMG (National Administration of Surveying, Mapping and Geoinformation), Shanghai 200092, China3 Shanghai Merchant Ship Design and Research Institute, Shanghai 201203, Chinashow less
Fig. 1. Point cloud 1 and point number-curvature distribution. (a) Point cloud 1; (b) point number-curvature distribution
Fig. 2. Point cloud 2 and point number-curvature distribution. (a) Point cloud 2; (b) point number-curvature distribution
Fig. 3. Point cloud compression method based on curvature grading
Fig. 4. Diagram of curvature grading based on logarithmic function
Fig. 5. Effect of compression control factor on curvature level
Fig. 6. Cloud data before compression and the results of three compression methods. (a) Original data; (b) compression result using Geomagic software; (c) compression result using the method in Ref. [8]; (d) compression result using the method proposed in this paper
Fig. 7. A local area and compression results under different compression ratios. (a) Original data of a local area; (b) compression ratio 70%, S=53.0; (c) compression ratio 80%, S=10.5; (d) compression ratio 90%, S=1.1
Fig. 8. Surface model built before compression and after compression by three methods. (a) Model built from original data; (b) model built from result compressed by Geomagic software; (c) model built from result compressed by the method in Ref. [8]; (d) model built from result compressed by the method proposed in this paper
Thre-sholdH0 | Compressioncontrolfactor S | Numberof originalpoints | Number ofremainingpoints | Com-pressionratio /% |
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0 | 1000 | 638122 | 284857 | 55.36 | 0 | 100 | 638122 | 250951 | 60.67 | 0.00002 | 50 | 638122 | 189597 | 70.29 | 0.00002 | 10 | 638122 | 126205 | 80.22 | 0.00002 | 1 | 638122 | 62206 | 90.25 |
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Table 1. Compression results of different thresholds
Compressionmethod | Compressionratio /% | Area beforecompression /cm2 | Area aftercompression /cm2 | Area changerate /% |
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Method in Geomagic | 70 | 8696.952 | 8687.918 | 0.104 | | 90 | 8696.952 | 8678.499 | 0.212 | Method in Ref. [8] | 70 | 8696.952 | 8689.584 | 0.085 | | 90 | 8696.952 | 8682.156 | 0.170 | Method in this paper | 70 | 8696.952 | 8690.274 | 0.077 | | 90 | 8696.952 | 8687.663 | 0.107 |
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Table 2. Comparison of area changes of different compression methods