Updated patch for Detecting Duplicates in F-Spot

[Indulis Bernsteins <indulis b au1 ibm com>]

Alvaro,

I think what you're doing is very importan
and usefult- can I suggest an idea I've been thinking about for a while
to extend what you've been doing?  I'm not suggesting you code this
personally :-)

What about also using the EXIF data,
as well as the filename, date modified, and other "metadata"
(implicit or explicit).

If you have 2 images, you can easily
look at the EXIF information common between the 2.  If the camera
body serial number is the same, and the date/time of shooting is the same,
and the EXIF stored image name is the same, you don't have to check the
MD5 sum to know that the 2 are at least derived from the same image.  You
can then just check file size.  If they are the same, then you've
got a match.

When you apply for a passport in Australia,
each piece of ID you show has "points" associated with it, when
you get to the right # of points, you can get a passport.  A similar
thing could be done for images and the user can select the metadata to
use (inc explicit metadata like info in f-spot's database and in the EXIF,
as well as "implicit" metadata like filesize and filename), and
the weightings applied to each factor to see that one image "qualifies"
to be a copy (or derivative) of another image.

I've also been thinking that it'd be
possible to implement an approach where the images are recognised as not
just being the same, but also derived from the same image.  This metadata
is currently constructed when f-spot creates a new image, so there is an
"original" and copies.

The long term aim would be to be able
to use the classification of related images to allow the user to set a
policy for their images.  For example, "I want the original kept
in this directory, and a copy in this directory.  I'd also like a
small version (640x480 or as close as you can get to this) in this directory,
kept for 12 months only. I'd also like 2 copies on off-line storage (CDs).
 Then I'd like a medium size copy uploaded to Flickr."  Then,
f-spot can use its knowledge about related images to make sure that all
of the images have had a second copy made, and have been shrunk down- if
not, this can happen in the background.  And if you want to change
your policy, for example, to have 3 copies, or store your photos stored
in directories sorted by the predominant colour, f-spot automagically does
this for you without you having to manually make the changes.  Duplicate
photos would be simply deleted (according to your policy)

I think there is a real advantage to
losing the "filesystem" oriented approach to managing images,
and moving to a metadata-based one.  f-spot could become not just
an image viewer, but also a darn good image manager!

Cheers,

Indulis