By combining the raster-vector conversion library and template matching,
the function of arrow recognition is used to extract arrows in route value maps in bulk.
Only arrows other than roads and district division symbols can be extracted.
The information of the recognized route value and leasehold ratio by the character recognition library and the information of arrows are output in connection.
It is also possible to integrate the information of eight adjacent route value maps including the directions of up, down, left, right, and diagonally.
Even if the arrows penetrate multiple drawings, they can be integrated.