A semantic based framework for
managing, searching and retrieving 3D
resources
Marios Pitikakis
CERETETH and University of Thessaly
Chiara Catalano
IMATI-CNR

AIM@SHAPE main achievements
Resources (data repositories) and knowledge have been
integrated into a unified Digital Shape Workbench
(DSW) interface.
All components are linked through ontological
structures (“knowledge technologies for shapes”).
Main services supported:
uploading of resources (models, tools, bibliographic
references etc);
advanced searching (SSE & GSE), browsing and downloading
resources;
management of resource metadata (i.e. insert/edit/delete
metadata);
management and maintenance of ontologies.
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

Technological achievements
Digital Shape Workbench (DSW)
knowledge management system & services
searching and browsing
Resources Knowledge
• shapes/models • domain and common ontologies
• tools/software • metadata for models & tools
• publications • glossary
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

DSW publicly available content
Shape Repository
Over 1000 models (1800000 visits, 85000 model downloads)
A lot of high quality models scanned with laser scanners
Tool repository
82 software tools or libraries
Digital library
2821 references in the field
Glossary (372 terms)
Shape ontologies
5 ontologies defined (2 common ontologies and 3 domain ontologies)
Publications
350 scientific papers, books, special issues
People and Institutions
13 partners, 101 researchers, 82 phD students involved
42 Network Interested Researchers’ Group (NIRG) members
31 Network Industry Group (NIG) members
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

DSW Knowledge Infrastructure Design
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

DSW Knowledge Infrastructure
Ontology Server
The role of the Ontology Server is to integrate the
SSE, the Inference Engine and the OMR.
Ontology and Metadata Repository (OMR)
The OMR is an ontology management system and
constitutes the knowledge base back-end of the
DSW.
Semantic Search Engine (SSE)
Inference Engine (RacerPro v1.9)
Several protocols and APIs
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

Knowledge base content
The Ontology and Metadata Repository contains
metadata for
1000+ models,
80+ tools/software,
220+ instances for Users and Institutions,
3500+ context-dependent instances in the domain and
common ontologies.
This large knowledge base provides a measure of the
scalability of the DSW infrastructure.
It has also provided a solid test base for the evaluation
of the efficiency of the SSE.
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

Common Shape Ontology
CSO: over 2500 instances
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

Shape Representation class hierarchy
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

Domain ontologies
Virtual Humans ontology (VHO)
Shape Acquisition and Processing ontology
(SAP)
Product Design ontology (PDO)
A large number of instances have been added
VHO: over 200
SAP: over 100
PDO: over 150
Tutorials of the ontologies can be found in the
DSW web pages.
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

Browsing-Searching
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

Shape Repository
Common Shape Ontology
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

Variety of models
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

Shape Repository
Range images Raw
Quad
Uniform
Groups, and sub-group levels
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

Shape Repository
Metadata
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

Shape Repository
Download / Visualization Features
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

Example Scenario
Physical
• Acquisition
Digital • Reconstruction
Geometry • Processing
• Structuring
Structure
Semantic
Bimba con nastrino
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

Insertion into the Shape Repository
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

Second example scenario
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

Geometry-based Search Engine
Goal: to search the Shape Repository of the
DSW according to geometric similarity
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

Overall Functionalities
The geometric similarity between shapes is evaluated as a distance between
descriptions of the shape that capture relevant properties of the shape
The main ingredients are
Tools for computing shape descriptors
Tools for computing distances between shape descriptors (comparison
methodologies)
Tools for computing shape descriptors and for computing distances between
shape descriptors are implemented as stand-alone tools that can be
plugged into the GSE
The GSE works with different matching criteria depending on the shape
descriptors and the comparison methodologies available (e.g. global or
partial matching)
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009

Comparison methodologies
Five comparison methodologies
 Structural descriptors
1. matching algorithm for attributed
directed graphs
2. matching algorithm for directed
graphs
 Topological descriptor
1. matching algorithm based on the Matching distance
2. matching algorithm based on the Hausdorff distance
 Geometric descriptor
1. Euclidean distance between feature vectors
VSMM 09, Workshop on 3D Knowledge Technologies for Cultural Heritage Applications, 12 Sept. 2009