I've imported lots of pictures into Shotwell and spent some time setting tags. Are those tags locked-in in Shotwell or I can export them (and import again or use with other software)?
I'm the founder of Yorba, makers of Shotwell. Thanks for your question.
Shotwell 0.7 writes metadata (such as tags and titles) to photos when you export them. The metadata is written in EXIF, IPTC and/or XMP format (depending on which of these were present in the photo to begin with). Most other photo programs can read these formats, so if you export your photos from Shotwell then other programs should be able to read their tags with no problem.
The upcoming Shotwell 0.8 can write metadata to photo files on the fly - to enable this, select the option "Write tags, titles and other metadata to photo files" in the preferences dialog. Once this is selected, Shotwell will update metadata in photo files as soon as you tag them. To use this feature, build the Shotwell trunk from source (see http://yorba.org/shotwell/install/#source), or just wait for Shotwell 0.8 (which we plan to release later in December).
Unfortunately Shotwell does seem to keep the tags in its own database rather than embed them as exif,IPTC or XMP in the pictures, you can check by using exiftool, exiftool can be installed by installing the package libimage-exiftool-perl , available in the repositories.
See some examples here; http://www.sno.phy.queensu.ca/~phil/exiftool/
use the command;
The exiftool utility can tag your pictures embedding the tags in the photo and the good thing about this is that most photo managers will use them, this includes Shotwell. Example:
Replace existing keyword list with two new keywords (favourite and family). When testpicture.jpg is imported into Shotwell the picture will be tagged with favourite and family
It may be helpful to know that the Shotwell database is an sqlite database located in your;
There are a few GUI frontends for sqlite, there is one for firefox here or you can use sqliteman , both of these front ends have export to csv features, when you export your tags to csv (Comma Separated Values) you can check if any other photo management software will import and map the tags to the appropriate field in their own databases, I believe Digikam can do this. Digikam can also embed exif data in the photos themselves.
Hopefully as Shotwell gain more features this situation will change.
UPDATE: While it is true that Shotwell 0.7 does not store its tags in the pictures as these tags are created, the tags can be embedded in the pictures if you choose to export them, thanks Adam for making this clear. Hopefully this export is lossless when dealing with jpegs. I suspect it is, if one selects original size for the Scaling option in the export dialog.
Quick (dirty?) python code to do this without upgrading Shotwell (I think as of 0.8.x Shotwell can write out tags, but you can't upgrade to that on Lucid). This thing will write out star-ratings as tags (comment that bit out, obviously, if you don't want that).
Requires exiftool. It'll duplicate any tags that are both in the shotwell database AND the images (ie ones that Shotwell imported when it imported the images) so watch out for that. Also, takes quite a while for a big collection of photos.
If you want a really good GUI tool/browser that will let you tag your images using Exif tags (and therefore available in Shotwell too), I recommend jBrout.
To install it, go to Synaptic, choose settings/repositories, click on the "Other Software" tab, then hit the "Add" button and paste in this line :
Then reload and search for jBrout.
Hmmm... you can read it :-) It has CVS export feature.
This is not normal GUI approach but there is a way.