Vectorial Distortion For Performance Evaluation Current investigations

1
Vectorial Distortion For Performance
EvaluationCurrent investigations .

• Mathieu Delalandre and Ernest Valveny
• Meeting of Document Analysis Group
• Computer Vision Center
• Barcelona, Spain
• Thursday 21th February 2007

2
IntroductionPerformance Evaluation of Graphics
Recognition Systems
Synthetic Document
Groundtruthing
Binary Noise
Vectorial Distortion
3
IntroductionVectorial Distortion
Document Understanding
Existing methods produce no real distortions
Noise related to image processing
How to improve them ?
Computer Aided Design
Noise related to layer model and viewer
Vectorial noise is liked to a produce model
On-line sketch
Noise related to user
4
IntroductionHand-Sketch Distortion
How to define a system allowing to generate
realistic distortion
CVC Database
The purpose is to copy realistic noise
To do a characterisation process
True-life Database
Characterisation Process set of criteria
43 classes, 5370 symbols
System proposal
Main features of hand-sketches
5
Characterisationin progress

• sketch proportions are few respected

dx
dy
symbol (s) and model (m)
6
Characterisationin progress

• straight lines look like curves and orientations
  are few respected

7
Characterisationin progress

• relative positioning of strokes are
• respected but not junctions

users use stroke sequences
8
First SystemCurrent proposal
21,13,34 42 76,65,54
Stroke sequence
Line graph
Model
9
First SystemCurve Distortion
Barraud05 Bezier approximation
Bezier curve
Bernstein polynomial
Obtained points correspond to control point Pi of
Bezier curve
(1) Line split to polyline using a regular
gap (2) Circle projection of points using a
parameter
10
First SystemCurve Distortion

• Barraud05 clipping effect

(1) Split the curve according dominant control
point (2) Delete a fixed rate of smallest curves
11
First SystemCurve Distortion

• Proposed improvements

fs0.08
fs0.1
(1) To formalize the point selection as a
sampling process
(2) To perform a random selection of points
(3) To use a Gaussian projection of points
12
First SystemLine Shock

• ICDAR07

13
Questions and Discussions