Time synchronization [was: GPS geotagging: first steps to implementation]

Am Montag, den 30.08.2010, 23:35 +0200 schrieb massimo citterio:
> 0 sync 2 or more camera time (usually my two cameras and my gps-cell
> phone have different time)

This is actually a much more difficult topic than one might think at

Syncing cameras to each others is of no use. Syncing the pictures of
cameras to UTC is the key, since GPS data always has accurate
UTC-timestamps by design.

But how to determine the time-difference between your camera and UTC?

The computer running f-spot can be set to UTC accurately enough by ntp.
Then we can encode the UTC time graphically by a 2D barcode and take a
picture of it. This picture then carries the UTC time it was taken at as
2D barcode and the camera time it was taken at as EXIF tag. It can be
detected easily and the time difference of camera and UTC (which is
equal to GPS time) can be read automatically from the picture and
applied to all pictures of the same import. Maybe even saved to adjust
later imports by the same camera (detected by the EXIF headers).

This is just a preparatory step for syncing GPS data and pictures, for
which accurate EXIF times are crucial.

Actually I have the idea sitting in my desk drawer since a while and
programmed a prototype last year, but never got around to finish or
publish it. By now the plugin is way out of sync to the current codebase
and I'd recommend a new implementation.

I hope you guys like the idea because I really would love to see this
unique feature implemented in f-spot.


Attachment: signature.asc
Description: Dies ist ein digital signierter Nachrichtenteil

[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]