Developer discussion for Creative Commons technology and tools

[Jon Phillips <jon AT rejon.org>]

On Sun, 2006-07-30 at 19:35 -0700, Mike Linksvayer wrote:
> One of the http://wiki.creativecommons.org/Summer_of_Code_2006_Projects
> is addressing EXIF, though I haven't seen the code yet...

I created a page for those interested in getting and putting metadata
into the filetypes which use Exif:

http://wiki.creativecommons.org/Exif

There are a gazillion tags
(http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/index.html) for
Exif metadata, so we need to pick a solid approach for pushing Exif
support to the 30 file formats that allow one to use Exif metadata.

After looking at the file list, one can see that support for Exif is
pretty major (more than id3) and there are tools, like exiftool
(http://www.sno.phy.queensu.ca/~phil/exiftool) which allow people to
embed and retrieve Exif metadata in quicktime, mp4, tiff, etc.

It looks like there are a several tag types with the basic Exif types
and then extended sets such as XMP. I think we should promote both using
the standard and XMP metadata types.

I think the best way to support Exif metadata is to use the XMP:cc and
XMP:dc (dublin core) tags to support metadata in a similar way as we do
with XML. What do you all think?

Also, I think supporting the standard Exif metadata tag "Copyright",
which is a string would be important as well: 

    0x8298 Copyright string IFD0

And possibly the Comment type as well:

    0x9286 UserComment undef ExifIFD

And, optionally, maybe we should promote adding the nonstandard XP
fields so that this metadata is available in Windows XP and greater: 

0x9c9b XPTitle undef IFD0 (tags 0x9c9b-0x9c9f are used by Windows
Explorer; special characters in these values are converted to UTF-8 by
default, or Windows Latin1 with the -L option. XPTitle is ignored by
Windows Explorer if ImageDescription exists) 

0x9c9c XPComment undef IFD0   

0x9c9d XPAuthor undef IFD0 (ignored by Windows Explorer if Artist
exists) 

0x9c9e XPKeywords undef IFD0   

0x9c9f XPSubject undef IFD0



Thoughts?

I'm also cc'ing Hubert Figuiere, who has worked on this filetype
extensively. Hubert, could you help us find out the best way to embed
licensing using Exif? These resource might exist, but hopefully you can
help us find them.

Jon

> On Mon, 2006-07-31 at 00:28 +0200, Jaime Frutos Morales wrote:
> > I'm new to this list, so hi you all!
> > 
> > I've searched the wiki for an EXIF metadata specification but I
> > haven't found any. Do you have any standard way of embeding CC
> > licenses in EXIF metadata?
> > 
> > There is a "Copyright" field which could be used to embed the CC
> > license. Any comments about this?
> > 
> > I'm interested in this because I'm planning to write a patch for EOG
> > (Gnome's image view program) to support CC licenses. At the moment,
> > I've only found an image metadata specification for SVG (and possibly
> > EXIF). Is there any other image format which supports embedded CC
> > licenses?
> > 
> > Thanks.
-- 
Jon Phillips

San Francisco, CA
USA PH 510.499.0894
jon AT rejon.org
http://www.rejon.org

MSN, AIM, Yahoo Chat: kidproto
Jabber Chat: rejon AT gristle.org
IRC: rejon AT irc.freenode.net

Inkscape (http://inkscape.org)
Open Clip Art Library (www.openclipart.org)
Creative Commons (www.creativecommons.org)
San Francisco Art Institute (www.sfai.edu)