[vox-tech] .jpg Mystery

[Bill Kendrick]

On Thu, Jan 21, 2010 at 10:35:35AM -0800, Bob Scofield wrote:
> In Linux there are a couple of different ways I can get the date and time the 
> photo was taken.

I picked a random photo I took with a Canon digital camera a few years ago.
The date/timestamp of the file on my laptop was from 9:05pm on the day
the photo was taken.

However, using "File->Properties..." in Gwenview, and looking at the
metadata stored in the file itself, it was stamped as 8:05pm of that day.

I'm guessing the timestamp in the metadata is off by an hour because
I never adjusted the clock inside my camera to account for Daylight Savings
time change.  (In other words, the camera THOUGHT it was 8:05pm, so that's
the metadata it stored.)

Note that it's probably quite trivial to tweak the timetamp of a file
and/or the metadata within the file.  Or, in my case, for the times to simply
be all screwed up since the device didn't know the correct time.

(My answering machine is a good example of a clock that needs
hand-holding: it always resets to "Monday, January 1, 12:00am" when its
power is cycled.  It doesn't know what year it is or what time zone it's
in, and (therefore) it cannot adjust for daylight savings or leap years.)


BTW - I am not a forensics guy, and I don't even really know much about
image file metadata.

-- 
-bill!
Sent from my computer