Fossgis: openstreetmap and airial pictures - Holger Neubert¶

Tags: fossgis, geo

As he wanted to be able to visit people at the other end of Germany in the weekend without standing in line on the Autobahn. So he bought a small airplane :-)

As he was also interested in openstreetmap, he fitted it out with a camera that can take pictures every five minutes. Big problem: lots of images aren’t usable because of motor vibrations.

For openstreetmap, most airial pictures are not usable due to licensing. Only exception: Bing. Also, most airial pictures aren’t very current. His goal is to make airial pictures with a reasonable quality (at least enough for OSM’s goal).

He used tools like prune to give GPS coordinates to the pictures based on their time and on the GPS track that his airplane gave him.

Something like warper can be used to warp the image a bit as there’s always some distortion. Warper offers a split screen with left the picture and right openstreetmap. You add control points to both and your picture is warped automatically.

An alternative: piclayer, a Josm plugin. That allows you to overlay your map with a picture and warp the picture yourself. The advantage is that it is much clearer visually what you’re doing.

A problem: height differences. This throws off the regular possibilities of the two warp tools above. Ideal: photogrammetry, but he doesn’t know of any open source software that does that.

Current situation:

• Some 10.000 pictures.

• Mostly geotagged.

• Partially callibrated.

• Available on http://wiki.openstreetmap.org/wiki/User:MartinDornfelder .

He could use help!