Local Structural Analysis: a Primer

1
Local Structural Analysis a Primer

• Mathieu Delalandre¹ , Eric Trupin¹, Jean-Marc
  Ogier²
• ¹PSI Laboratory, Rouen University, France
• ²L3I Laboratory, La Rochelle University, France

2
Plan

• Introduction
• General Decomposition
• Method Comparison
• Method Combination
• Conclusion

3
Plan

• Introduction
• General Decomposition
• Method Comparison
• Method Combination
• Conclusion

4
Introduction

• shape recognition process
• statistical analysis and recognition (Jain 2000)
• structural analysis and recognition (Tombre 1996)

feature extraction or analysis (Loncarnic 1998)
recognition
ltnetworkgt ltpart id1gt ltsymbolsgt ltlabelsgtlt/labels
gt lt/symbolsgt lt/partgt lt/networkgt
5
Introduction

• structural recognition
• graph-matching approach (Hancock 2002)
• grammar approach (Blostein 1995)
• structural analysis

6
Plan

• Introduction
• General Decomposition
• Method Comparison
• Method Combination
• Conclusion

7
General Decomposition

• four steps

object graph extraction
mathematical approximation
high level object construction
object graph correction
8
General Decomposition

• step 1, object graph extraction (1)

skeletonisation
contouring
run
tracking


meshes
region
segmented object
9
General Decomposition

• step 1, object graph extraction (2)
• skeletonisation based methods, two steps
• skeletonisation (Lam 1995)
• skeleton graph extraction (Tombre 1999)(Lau 2002)
• contouring based methods
• morphological based methods (Hasan 2000)
• following based methods (Ablameyko Pridmore
  2000)
• tracking based methods, two tracking types
• line tracking (Song 2002)
• junction tracking (Ogier 1992)

10
General Decomposition

• step 1, object graph extraction (3)
• run decomposition based methods
• vertical and horizontal run graph (Burge 1998)
• region decomposition based methods
• orientation map (Cao 2000) and wave aggregation
  (Delalandre 2003)

11
General Decomposition

• step 1, object graph extraction (4)
• meshes based methods, two steps (vaxivière 1995)
• image is splited up into meshes
• meshes are recognized according to a library
• segmented based methods, two segmentations
• line, circle and ellipsis segmentation (Matas
  1999) (Su 2002)
• junction segmentation (Chen 2000)

12
General Decomposition

• step 2, mathematical approximation
• vector, circle, and curve fitting (Rosin 1995)
• step 3, high level object construction
• circle reconstruction (Hilaire 2001)
• contour matching (Zou 2000) (Ramel 2000)

13
General Decomposition

• step 4, object graph correction, some examples
• pruning merging (Delalandre 2003)
• junction fusion (Lin 2002)
• vectorial correction (Hilaire 2001)

14
Plan

• Introduction
• General Decomposition
• Method Comparison
• Method Combination
• Conclusion

15
Method Comparison

• object graph extraction, seven criteria

• Junction junction detection
• Morphology various shape analysis
• Invariance scale and orientation change
• Sensitivity noise resistance
• Semantic low or high level object
• Reversibility image return
• Complexity low algorithmic complexity

16
Plan

• Introduction
• General Decomposition
• Method Comparison
• Method Combination
• Conclusion

17
Method Combination

• comparison combination
• different analysis and recognition, then
  comparison
• ? multi representation
• skeletonisation and contouring (Nakajima 1999)

18
Method Combination

• hybrid combination
• different analysis, then hybrid graph
  construction and recognition
• ? multi representation
• run and skeleton graph (Xue 2001)
• region graph and statistical description
  (Delalandre 2003)

19
Method Combination

• cooperative combination
• first analysis in order to help the second
  analysis
• ? process simplification
• object simplification (Song 2002)

20
Plan

• Introduction
• Global Structural Analysis
• Local Structural Analysis
• Method Combination
• Conclusion

21
Conclusion

• local structural analysis
• connected component ? graph
• 4 main steps
• 7 criteria of comparison
• method combination
• a research perspective
• ? multi representation (structural and
  statistical-structural)
• ? process simplification