GPS Coordinate Editor Using Flash and Google Maps

The above is a demo of a GPS coordinate editor. The demo loads over 2500 timestamped coordinates and determines the coordinates which are most characteristic, the keypoints. All other points get discarded.

This Flash map editor has the following functionality:

• Click markers to select/deselect them
• Press the 'x' key to remove selected markers.
• Click and drag markers to move them
• Shift+click to select additional markers
• Ctrl+click to deselect markers
• Shift+click or ctrl+click and then drag to use a selection box for selecting/deselecting markers
• Click on the map to clear the selection or, if no selection, add a marker on the nearest line

This was designed for personal use so it might not be the most intuitive UI. Once you get used to it, though, editing is pretty quick.

When adding nodes, the timestamp and altitude values are interpolated from the adjacent points.

The two images show the keypoint-detection algorithm at work. The white markers have only been filtered using a minimum distance filter. The red markers are chosen where the change in direction goes beyond a certain threshold. This ensures that you get a decent approximation of the line without storing hundreds of points.

If you have any comments or suggestions for the interface go ahead and post in the comments below.