Map change detection device, map change detection method, and program
Changes in houses and buildings on a two-dimensional map are detected using three-dimensional data obtained from stereo images. A change detection device that detects changes in features that are targets described on a map has a stereo processor, a feature height calculator, and a demolition and/or new building detector. The stereo processor is inputted with a plurality of images taken of predetermined regions from a plurality of different positions, and extracts digital surface model data representing surfaces of the regions in three-dimensional coordinates. The feature height calculator extracts feature heights where an elevation of ground level is subtracted from the digital surface model data extracted by the stereo processor. The demolition and/or new building detector detect changes in the feature that are the targets described on a map by comparing feature height data and map data. An elevation region extractor extracts an elevation region that is a set of points having a height greater than or equal to the predetermined value, compares the elevation region and the map data, and detects changes in the feature constituting the targets.
1. A map change detection device that detects changes in features that are targets described on a map, the map change detection device comprising:
a stereo matching processor that, inputted with a plurality of images taken of predetermined regions from a plurality of different positions, extracts digital surface model data representing surfaces of the predetermined regions in three-dimensional coordinates;
a feature height extractor that extracts feature heights where an elevation from ground level is subtracted from the digital surface model data extracted by the stereo matching processor; and
a change detector that detects changes in a feature that is the target by comparing feature height data extracted by the feature height extractor and map data.
2. The map change detection device according to claim 1 , wherein the change detector extracts an elevation region that is a set of points, of the feature height data, having a height greater than or equal to a predetermined value, compares the elevation region and the map data, and detects changes in a feature that is the target.
3. The map change detection device according to claim 1 , wherein the change detector detects changes in a feature that is the target when:
the feature height data is a plus quantity at a point where the feature that is the target does not exist in the map data; or
the feature height data is a predetermined value or less at a point where the feature that is the target exists in the map data.
4. The map change detection device according to claim 2 , wherein the change detector detects changes in a feature that is the target when:
the feature height data is a plus quantity at a point where the feature that is the target does not exist in the map data; or
the feature height data is a predetermined value or less at a point where the feature that is the target exists in the map data.
5. The map change detection device according to claim 2 , wherein the change detector detects change in a feature that is the target when a one portion set of the elevation region exceeds a predetermined density and exceeds a predetermined area at a region where a feature that is the target does not exist in the map data.
6. The map change detection device according to claim 2 , wherein the change detector detects changes of the feature when the elevation region is a predetermined area or less within an arbitrary feature of the map data.
7. A map change detection method performed by a map change detection device, for detecting changes in features that are targets included in a predetermined region on a map, comprising:
stereo matching processing by a stereo matching processor of the map change detection device where a plurality of images taken of predetermined regions from a plurality of different positions are inputted and digital surface model data representing surfaces of the predetermined regions in three-dimensional coordinates is extracted;
feature height extraction by a feature height extractor of the map change detection device where feature heights where an elevation from ground level is subtracted, are extracted from the digital surface model data extracted by the stereo matching processing; and
change detection by a change detector of the map change detection device where changes in a feature that is the target by comparing feature height data extracted in the feature height extraction and map data are detected.
8. The map change detection method according to claim 7 , wherein an elevation region that is a set of points, of the feature height data, having a height greater than or equal to a predetermined value is extracted, the elevation region and the map data are compared, and changes in a feature that is the target are detected by the change detector during the change detection.
9. The map change detection method according to claim 7 , wherein changes in a feature that is the target are detected by the change detector during the change detection when:
the feature height data is a plus quantity at a point where the feature that is the target does not exist in the map data; or
the feature height data is a predetermined value or less at a point where the feature that is the target exists in the map data.
10. The map change detection method according to claim 8 , wherein changes in a feature that is the target are detected by the change detector during the change detection when:
the feature height data is a plus quantity at a point where the feature that is the target does not exist in the map data; or
the feature height data is a predetermined value or less at a point where the feature that is the target exists in the map data.
11. The map change detection method according to claim 8 , wherein changes in a feature that is the target are detected by the change detector during the change detection when a one portion set of the elevation region exceeds a predetermined density and exceeds a predetermined area at a region where a feature that is the target does not exist in the map data.
12. The map change detection method according to claim 8 , wherein changes of the feature are detected by the change detector during change the change detection when the elevation region is a predetermined area or less within an arbitrary feature of the map data.
13. A non-transitory, tangible computer-readable medium that stores a program for implementing, on a computer:
a stereo matching processor inputted with a plurality of images taken of predetermined regions from a plurality of different positions, that extracts digital surface model data representing surfaces of the predetermined regions in three-dimensional coordinates;
a feature height extractor that extracts feature heights where an elevation from ground level is subtracted, from the digital surface model data extracted by the stereo matching processor; and
a change detector that detects change in a feature that is the target described on a map by comparing feature height data extracted by the feature height extractor and map data.