On 6/4/07, Lars Aronsson lars@aronsson.se wrote:
Andre Engels wrote:
When would someone like to use that picture in Wikipedia or a Wikibook or whatever? When they're talking about the village, I assume.
This position is untenable. Have you tried to geotag any significant amount of images that way? You cannot accurately measure the latitude and longitude of the object you are capturing. It might be quite large. Or it might be two different objects at different locations (another building in the foreground and the Eiffel tower far behind). The only sustainable policy is to register the point position of the photographer and, if possible, the pointing direction of the lens.
If you're going to do that, might as well include some indication of the effective focal length.
But that's far from the *only* sustainable policy. In fact, in some cases it is impossible to know the position of the photographer but it is possible to know the position of the subject. A good geotagging system is going to allow for both - informally if not formally.
If you want to find
photos of the Eiffel tower, you need to search for photos that are tagged in a surrounding region.
So a satellite photo of the Eiffel tower would be tagged with the position of the satellite? Doesn't seem reasonable.
There is a discussion and illustration at
Right, take that photo in the example and pretend we don't know the position of the photographer. Also assume we don't know the focal length, or type of camera, or even whether or not the image has been cropped. There's no easy way to extract the location of the photographer from just that photograph. You can, however, tag the image with the location of one of the two buildings, or even both of the two buildings. If you do know the location of the photographer, you could even tag all three points, hopefully with some metadata saying that one of the three points was the photographer's location.