Patent ID: 8483425

Claim:
A geospatial information creating system for extracting a footprint of a house from an aerial photograph, comprising a processor for executing a program, a memory for storing data required for executing the program, and a storage unit for storing the aerial photograph, wherein the processor is configured to: detect edges of an image based on a characteristic quantity of neighboring pixels in the aerial photograph stored in the storage unit; extract an orientation of the house by analyzing directions of the detected edges; generate a polygon of an outline of the house by using linear lines of the extracted orientation of the house; receive specification of a position by an operator for the house to extract the footprint; determine a house area by an extent covered by extracted edges by periodically extracting neighboring pixels more similar than a threshold before extraction of the edges; and change the threshold by decreasing it, and extract again neighboring pixels more similar than the changed threshold in the case where the determined house area does not include the specified position.