CMA Coastline Matching Algorithm SSIP’99 - Project 10 Team H

Joonas Lehtinen Finland Marcell NagyHungary József GalajdaHungary Róbert VányiHungary

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

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.

Parts of the project Preprocessing Chain code generation Detection Documentation

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

Preprocessing Original image

Preprocessing Yellow component

Preprocessing Gradient with tresholding

Chain code generation Preprocessed images Cleaning images Thinning process Coordinate list generation Chain code calculation

Chain code generation Preprocessed image

Chain code generation Cleaned coastline

Chain code generation Thinned coastline

Chain code generation Coordinate list

Chain code generation Chain code

Detection Error function Searching algorithm

Error function

Searching algorithm

Documentation Web page Changes file Header file Presentation

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

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