1. Vectorial Distortion For Performance Evaluation Current investigations …. Mathieu Delalandre and Ernest Valveny Meeting of Document Analysis Group Computer Vision Center Barcelona, Spain Thursday 21th February 2007

2. Introduction Performance Evaluation of Graphics Recognition Systems Binary Noise Groundtruthing Synthetic Document Vectorial Distortion

3. Introduction Vectorial Distortion You see 5 You have 9 Noise related to layer model and viewer Noise related to user Noise related to image processing Document Understanding Computer Aided Design On-line sketch How to improve them ? Existing methods produce no “real” distortions Vectorial noise is liked to a produce model

4. Introduction Hand-Sketch Distortion True-life Database Characterisation Process “set of criteria” System proposal How to define a system allowing to generate “realistic” distortion 43 classes, 5370 symbols Main features of hand-sketches CVC Database The purpose is to copy realistic noise To do a characterisation process

5. Characterisation in progress … sketch proportions are few respected” dxdx dydy symbol (s) and model (m)

6. straight lines look like curves and orientations are few respected Characterisation in progress …

7. relative positioning of strokes are respected but not junctions Characterisation in progress … users use stroke sequences

8. First System Current proposal Curve distortion Line shockScale distortion 1 23 4 5 6 7 {21,13,34} {42} {76,65,54} Line graph Stroke sequence Model Previous works

9. First System Curve Distortion Barraud’05 “Bezier approximation” (1) Line split to polyline using a regular gap (2) Circle projection of points using a parameter Obtained points correspond to control point P i of Bezier curve Bezier curve Bernstein polynomial

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

11. First System Curve Distortion Proposed improvements (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 f s =0.08f s =0.1

12. First System Line Shock ICDAR’07 variance: 0.001 0.005 0.010 scaling rotation moving v0 x s  [0,1] y v max (b)(a)

13. Questions and Discussions