Coastline Matching Algorithm for Fragment Detection in Map Data

2. Coastline Matching Algorithm SSIP’99 - Project 10 Team H

3. Team H Joonas Lehtinen Finland Marcell Nagy Hungary József Galajda Hungary Róbert Ványi Hungary

4. Introduction • Problem definition • Parts of the project • Preprocessing • Chain code generation • Detection • Documentation • Results, future work

5. Problem definition Match of fragment of coastline to map Starting off with a segment of coastline (or a river with bridges) from a map, of different scale and noise properties extracted from a (much) larger segment, perform best fit to identify the section of coastline. One method that could be used would be correlation of a chain code representation. Creation of chain code or equivalent from map segment is part of the project. Imagine satellite images.

6. Parts of the project • Preprocessing • Chain code generation • Detection • Documentation

7. Preprocessing • Start with scanned maps • Creating yellow component from CMY • Detection of the coastline • Box filtering • Robert’s gradient • Tresholding

8. Preprocessing • Original image

9. Preprocessing • Yellow component

10. Preprocessing • Gradient with tresholding

11. Chain code generation • Preprocessed images • Cleaning images • Thinning process • Coordinate list generation • Chain code calculation

12. Chain code generation • Preprocessed image

13. Chain code generation • Cleaned coastline

14. Chain code generation • Thinned coastline

15. Chain code generation • Coordinate list

16. Chain code generation • Chain code

17. Detection • Error function • Searching algorithm

18. Error function

19. Searching algorithm

20. Documentation • Web page • Changes file • Header file • Presentation

21. Results, future work • Map of Central America • Several coastlines and segments • Correct matches

22. Results, future work • Faster searching algorithm • Fully automatic preprocessing • Graphical User Interface • Less “coastline segmentation fault”