Picasa database format, export capability question

[ktenney]

Howdy,

I'm starting to use Picasa 3 for Linux.

Before I invest lots of time into tagging and captioning, I'd like to
know
that information is accessible from outside Picasa.

Is there a programming API for Picasa?
Is the database format documented?
Is it possible to export to some kind of text format: xml or csv?

Thanks,
Kent

[leiz]

Picasa stores comments and tags inside JPEG files as IPTC data. For
instance, I took foo.jpg and added "test_comment" along with the tags
"testtag1" and "testtag2" When I examine the file with exiv2 [1] as
follows:

exiv2 -pi print foo.jpg

I get:

Iptc.Application2.Caption String 12
test_caption
Iptc.Application2.Keywords String 8 testtag1
Iptc.Application2.Keywords String 8 testtag2

[1] http://www.exiv2.org/

[Kent Tenney]

leiz,

So Picasa changes the image file on disk when
a tag or comment is applied?

I consider that presumptious, I would prefer my original files
not be changed.

It would be great if the format of the Picasa database were
documented.

If Picasa developers follow this list I'd be interested in any
comments on the db format, and the wisdom of altering the
image files. Is this something that can be turned off?

Thanks,
Kent

[leiz]

I think tags/comments and red-eye (for whatever reason) are the only
operations that change your photos directly. I don't think it can be
turned off. Keep in mind this only changes the JPEG metadata, and
doesn't modify the image portion of the JPEG file.

The IPTC fields are standard fields that many photo apps understand.
Would you rather have Picasa store tags in some format that's less
exchangeable with other apps?

[Kent Tenney]

On Thu, Aug 13, 2009 at 3:03 PM, leiz<zhan...@gmail.com> wrote:
>
> I think tags/comments and red-eye (for whatever reason) are the only
> operations that change your photos directly. I don't think it can be
> turned off. Keep in mind this only changes the JPEG metadata, and
> doesn't modify the image portion of the JPEG file.

Right, not the 'image portion' of the file, but the file is being changed,
the date changes, the checksum changes, the size changes.

There are benefits of writing metadata to the image file, however
I prefer original images to be immutable.

>
> The IPTC fields are standard fields that many photo apps understand.
> Would you rather have Picasa store tags in some format that's less
> exchangeable with other apps?

If Picasa is going to write to my files, IPTC is probably fine,
though XMP seems to be the preferred currently.

Thanks,
Kent

[Janno Pugi]

There is no questions, tags must be saved to jpeg metadata, it's standard!

J.

2009/8/14 Kent Tenney <kte...@gmail.com>

[axxi]

Try to use exportpicasa utility (http://sourceforge.net/projects/exportpicasa/). It's beta now. And for win32 only. But I don't see nothing impossible to make it portable.