Face Detection and Modeling for Recognition - Biometrics Research ...
Face Detection and Modeling for Recognition - Biometrics Research ...
Face Detection and Modeling for Recognition - Biometrics Research ...
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are listed in Table 2.2.<br />
All of these compression methods focus on model represen-<br />
Table 2.2<br />
Geometric compression efficiency.<br />
Method<br />
Geometric<br />
Compression [137]<br />
Topological<br />
Surgery [75]<br />
Geometric<br />
Loss Measure Compressed feature<br />
Compression<br />
Ratio (GCR)<br />
6–10 slight losses Positions, normals,<br />
colors<br />
20–100 no loss Connectivity;<br />
12–30 N/A Positions, facet<br />
properties;<br />
20–100 N/A ASCII-file sizes<br />
Remeshing [138] 54–1.2 Remeshing & compression<br />
tolerances<br />
Level of detail<br />
(facets)<br />
tation using triangular meshes. However, <strong>for</strong> more complex 3D shapes, the surface<br />
representation using triangular meshes usually results in a large number of triangular<br />
facets, because each triangular facet is explicitly described. We have developed<br />
a novel compression approach <strong>for</strong> free-<strong>for</strong>m surfaces using 3D wavelets <strong>and</strong> lattice<br />
vector quantization [139].<br />
In our approach, surfaces are implicitly represented inside<br />
a volume in the same way as edges in a 2D image. A further improvement in<br />
our approach can be achieved by making use of integer wavelet trans<strong>for</strong>mation [140],<br />
[141].<br />
53