Point-set compression through BSP quantization A. Bordignon, T. Lewiner, H. Lopes, G. Tavares and R. Castro Departamento de Matemática – PUC-Rio
2 /22 Point sets
3 /22 Compression
4 /22 Contributions Geometry compression with geometry instead of combinatorics BSP quantization Progressive compression 15% improvements in compression ratios
5 /22 Overview Tree-based compression Cost repartition BSP generation Adaptative quantization Results
6 /22 Tree-based compression Recursive subdivision Ambient space combinatorics Point position RBLB LTRT RBLB LTRT RBLB LTRT LB RT LT
7 /22 Subdivision symbols
8 /22 Emptyness symbols
9 /22 Counting symbols
10 /22 Cost repartition count emptyness
11 /22 Previous blending
12 /22 Binary Space Partition Bet: much more information better distributed
13 /22 BSP construction Adapted to local statistic of points
14 /22 BSP compression Cut planes codes: Euler angles Subdivision codes: counting symbols
15 /22 Angles of the cut planes Euler angles
16 /22 Quantization a ≈0.5 φ ≈ 0 ψ ≈ 0
17 /22 Small cells guarantee 0 bit quantization: middle orthogonal cut regular cut to reduce the cell size 10 bits quantization 5 bits quantization 0 bit quantization
18 /22 Adaptation
19 /22 Compression Ratios EmptyCount Blend
20 /22 Progressive (bpv = bit per vertex) 0.33 bpv 1.30 bpv 4.06 bpv 8.52 bpv bpv
21 /22 For now... and next Won the bet: geometric symbols 15% improvement in compression ratio Won more: fast, adapted BSP construction explicit BSP cell with a local frame Next bet? Improve progressivity Progressive GEncode
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