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Point-set compression through BSP quantization. A. Bordignon, T. Lewiner , H. Lopes, G. Tavares and R. Castro Departamento de Matemática – PUC-Rio. Point sets. Compression. Contributions. Geometry compression with geometry instead of combinatorics BSP quantization - PowerPoint PPT Presentation
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Point-set compression Point-set compression through BSP quantizationthrough BSP quantization
A. Bordignon, T. Lewiner, H. Lopes,G. Tavares and R. Castro
Departamento de Matemática – PUC-Rio
2/22 Point setsPoint sets
3/22 CompressionCompression
4/22 ContributionsContributions
Geometry compression with geometry instead of combinatorics
BSP quantization
Progressive compression
15% improvements in compression ratios
5/22 OverviewOverview
Tree-based compression Cost repartition BSP generation Adaptative quantization Results
6/22 Tree-based compressionTree-based compression
Recursive subdivision
Ambient space combinatorics
Point position
RBLB
LT RT
RBLB
LT RTRBLB
LT RT
LB RT LT
7/22 Subdivision symbolsSubdivision symbols
8/22 Emptyness symbolsEmptyness symbols
+0 ++ ++ 0+ ++ ++ 0+
9/22 Counting symbolsCounting symbols
005 5 4 2 1 1
10/22 Cost repartitionCost repartition
count
emptyness
11/22 Previous blendingPrevious blending
++ +1 1+ 11 +0 0+
10 01
12/22 Binary Space PartitionBinary Space Partition
Bet: much more information better distributed
13/22 BSP constructionBSP construction
Adapted to local statistic of points
14/22 BSP compressionBSP compression
Cut planes codes: Euler anglesSubdivision codes: counting symbols
15/22 Angles of the cut planesAngles of the cut planes
Euler angles
16/22 QuantizationQuantization
a ≈0.5φ ≈ 0ψ ≈ 0
17/22 Small cells guaranteeSmall 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 AdaptationAdaptation
19/22 Compression RatiosCompression RatiosEmpty Count Blend
20/22 ProgressiveProgressive
(bpv = bit per vertex)
0.33 bpv 1.30 bpv 4.06 bpv 8.52 bpv15.35 bpv
21/22 For now... and nextFor 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
Thank you forThank you foryour attention!your attention!
http://www.mat.puc-rio.br/~tomlew