Creating a very simple revision system for photos in python

[Thomas W]

On 11 Mar, 17:23, Tim Golden <m... at timgolden.me.uk> wrote:
> On 11/03/2011 16:05, Chris Hulan wrote:
>
>
>
>
>
>
>
>
>
> > On Mar 11, 9:56 am, Thomas W<thomas.weh... at gmail.com>  wrote:
> >> I`m thinking about creating a very simple revision system for photos
> >> in python, something like bazaar, mercurial or git, but for photos.
> >> The problem is that handling large binary files compared to plain text
> >> files are quite different. Has anybody done something like this or
> >> have any thoughts about it, I`d be very grateful. If something like
> >> mercurial or git could be used and/or extended/customized that would
> >> be even better.
>
> >> We are talking about large numbers of photos and some of them are
> >> large in size as well, but the functionality does not have to be a
> >> full fledged revision system, just handle checking out, checking in,
> >> handling conflicts, rollbacks etc, preferrably without storing
> >> complete copies of the files in question for every operation.
>
> >> Thanks for any input. :-)
>
> > Most traditional revision systems excel at managing text, but suck at
> > binary.
> > I recall that Picassa has a revision system
>
> > It occurs to me you could use Uuencoding to make binaries more
> > amendable to
> > handling by text-oriented revision systems
>
> I'm not sure there's much point in doing that. Certainly Subversion,
> and I imagine the other main RCS, handle binary data perfectly well;
> I mean, they don't stop when they come across a NUL byte or anything
> like that. You can't do much with the result except retrieve it, but
> I'm not sure that uuencodeing (or any other encoding) adds anything
> there, either.
>
> FWIW TortoiseSvn offers an image-diff utility which superimposes the
> two versions of an image with an alpha blend (if that's what it's
> called). It's basically the electronic equivalent of holding two
> sheets of paper up to the light. Don't know if this helps the OP,
> mind you.
>
> TJG

Hmm ... encoding my photos using uuencoding will just eat up space, it
adds about 40% or so ( if I remember correctly ) to the total size of
the encoded file, a file which may allready be 10+ MB. That`s the
problem using git and friends as well; it creates full copies of the
files and that`s part of the thing I want to avoid, if possible.

Sounds like this is a task for more experienced users than me, but I`m
gonna take a stab at it anyway, allthough my ideas for a solution is
pretty basic and simple.

Anyway, thanks a lot for your input :-)

Thomas