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 You see 5 You have 9 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 1 2 3 4 5 7 6 Previous works Scale distortion Line shock Curve distortion {21,13,34} {42} {76,65,54} Stroke sequence Line graph Model

9. First SystemCurve Distortion Barraud’05 “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 Barraud’05 “clipping effect” (1) Split the curve according dominant control point (2) Delete a fixed rate of smallest curves

11. First SystemCurve Distortion Proposed improvements fs=0.08 fs=0.1 (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 scaling y rotation (a) (b) moving s [0,1] variance: 0.001 0.005 0.010 x 0 v vmax ICDAR’07

13. Questions and Discussions