Automated Partition and Classification of Maps for Area Estimation by Land Use

Abstract

A large-scale natural disaster leaves its traces on the map. Wide and precise analysis of the temporal change of the map gives detailed and quantitative information for disaster prevention research. Aiming to develop automatic or computer-aided map analysis system, this manuscript proposes an automatic classification method of modern Japanese maps by land-use, such as farmland, urban area, forestry, etc. For maps drawn manually and printed on paper medium, map symbols are recognized by template matching, broken border lines are completed by opening, and region is partitioned by labeling. As for the regions where boundary lines are omitted, the boundary is inferred based on the distance to the map symbol. An urban area is deduced from dense drawing and excluded from the area classification with the map symbols. A demonstration of the proposed method to plain region in Osaka on 1:25,000 map measured in the Taisho era showed about 74% of true positive rate and about 13% of false positive rate.