I support this request, as unimportant as it sounds... however, gthumb is really needing this (and also it'd be nice if it wrote the categories/collections of the image using exif so if something happens to the gthumb database, it can be reconstructed from the data in the exif of the pictures.

It might be possible to link the gThumb comments with the exif UserComments field, so that changing one would change the other. (I'm not sure what we should do if both the gThumb comment and the exif comment are non-null and are different...)

- Mike

I would appreciate this feature also.
It's the one thing missing from gThumb for me.

This feature is really missing. In case of both fields non-null, ask user what to do.

Thanks for good job and thanks in advance.

Hi,

I'm interested in this feature too. For that I decided to take a look at the code to figure out how hard it would be to implement it myself. But then I noticed that in the last svn version, it seems to be implemented. At least, if I now save a comment, I can find it in the file with a hexeditor, and eye-of-gnome and gwenview can also read it.
So can somebody confirm this?

Tom,

Yes, the trunk version attempts to read/write the comment data and tags from/to the exif or xmp metadata.

The preferred metadata fields are listed at the top of libgthumb/gth-exif-utils.c (see for example: 

const char *_COMMENT_TAG_NAMES[] = {
        "Exif.Photo.UserComment",
        "Exif.Image.ImageDescription",
        "Xmp.tiff.ImageDescription",
        "Xmp.dc.description",
        "Iptc.Application2.Caption",
        NULL };

The order of these tags determines where gThumb should first look for a comment, and the preferred writing tag is Exif.Photo.UserComment.

The comment code is in libgthumb/comments.c (search for "TAG_NAME_SETS").

This has not been extensively used by anybody other than me, so feedback is welcome.

General-purpose editing of arbitrary exif/xmp tags has not been implemented. For instance, you can't edit the camera serial number tag. However, it should be possible to do this. The metadata writing routines exist already. Basically, you could just make the treeview in src/gth-exif-data-viewer.c editable. Or you could create a fancier new dialog to do it.

- Mike

Michael,

The only thing I was really interested in was the ability to store comments inside the exif data, and that's what possible now. I'm actually not interested in modifying any other tags (I can't find a good reason to do so).

I'll try to tag my albums using gthumb from svn, and I'll let you know if I encounter problems.

I agree. This is a important missing feature. Why not using jhead as exif editor engine ? You just have to write code for a jhead front head ? Is this difficult to develop ?

For anybody who doesn't understand what this bug is about, try jbrout which does The Right Thing in this department IMHO, and read http://www.sitepoint.com/blogs/2006/08/24/open-source-image-archiving-exif-iptc-xmp-and-all-that/# or http://ceitl.zanestate.edu/blog/archives/2005/11/photo-organizing-in-linux/

Please try the current development version (ext branch). It syncs gthumb comments with the metadata.

http://live.gnome.org/gthumb

- Mike

and tags? do we have anything like it in gthumb? Can I manage my 3.7GB of pictures with gthumb now?

Created attachment 148813 [details]
screenshot illustrating the issue

I tried to add "zkušební" tag to this JPEG (http://mcepl.fedorapeople.org/tmp/p20091018_143552.jpg), it is there in Gthumb, but neither jbrout nor exiftool see it there:

bradford:~$ exiftool Obrázky/import/p20091018_143552.jpg |grep Keywords
Keywords                        : PepíÄek, Praha, doma, BDay
bradford:~$ 

(never mind, screwed up UTF-8)

(In reply to comment #12)
> (never mind, screwed up UTF-8)

it should read

never mind screwed up UTF-8

I think the "screwed up" tag prevents the correct metadata saving.

(In reply to comment #14)
> I think the "screwed up" tag prevents the correct metadata saving.

well, it is "screwed up" neither in jbrout or gthumb (see attachment 148813 [details] in comment 12; it's a word "Pepíček" which is displayed perfectly well by gthumb). Only exiftool doesn't do UTF-8 well, gthumb does.

ext branch uses exiv2 to read/write metadata. You might try the exiv2 command-line tool (instead of exiftool) and see if the problem lies with exiv2.

- Mike

I think we can close this bug since gthumb 2.12 saves the comment in the Exif description field as well.

After studying a lot of how other photo managers implement XMP tags (e.g., see http://trac.yorba.org/wiki/PhotoTags, http://trac.yorba.org/wiki/FSpotTags, or http://metadataworkinggroup.com/pdf/mwg_guidance.pdf), I believe that better than Xmp.iptc.Keywords would be to store tags in Xmp.dc.subject, but otherwise tags are really stored in images, so this is most likely really fixed.

Bug maintenance: changed status to "Resolved", to match the reported "Resolution".