The application, Picasa Face Tag Extraction, can be used to export face tags from photos managed by Picasa and then those tags can be attached to photos within Piwigo. Then, photos in Piwigo can be viewed or searched by face tag.
The folder names used by Picasa should match the album names used in Piwigo.
You'll have to open your mySQL database to the outside world, temporarily (at least to the computer you’re running the application from). The default condition of mySQL is to have external access disabled. I'm running ubuntu linux so I also had to open the mySQL port, 3306, in the OS. You can search the web for instructions - I found this article useful, http://endpoint.co/technology/enable-remote-access-mysql.
I recommend that you back up your Piwigo database. You can never be too careful! And, I would feel bad if I ruined your Piwigo installation. I used phpMyAdmin to do the backup, but you can also do it using command line. As above, I found a web search useful.
Picasa Contacts File – The contacts.xml file used by Picasa. In my case, the file was located at: c:\Users\admin\AppData\Local\Google\Picasa2\Contacts
Root Photo Path – The directory where you want the application to start reading photos from. The application will traverse sub-directories and it ignores any .picasaoriginals directories.
Output Path – Location where text and html output files are placed.
Generate HTML Files – When checked, simple HTML files will be created for each contact, with hyperlinks to each photo that the particular contact appears in. It may be useful if you want a simple web page with links to people’s photos.
Set Tags in Piwigo – When checked, the application will place Picasa face tags into the Piwigo database and tag corresponding photos. When the option is not checked, only text and html (if selected) files are generated.
Server Name – The IP address of the mySQL server.
Database – The name of database used by Piwigo. Usually it’s piwigo.
Database User Name – A mySQL account that has read/write access to the Piwigo database. I use root.
Database Password – You know.
Database Table Prefix – The prefix of the Piwigo database tables. Usually it’s piwigo.
Clear Existing Face Tags in Piwigo – When checked, deletes tags from the piwigo tag database before adding new tags. When checked, only face tags that appear in contacts.xml will be deleted from Piwigo. Other tags will not be affected.
Application will handle a maximum of 512 unique faces in Picasa.
If you’ve already tagged photos in piwigo using the application it will not re-tag them. So, it’s ok to run the application multiple times using the same photo directories.
This application was verified with Piwigo database version 2.4. The application validates the database version number and offers the user the chance to abort if there is a version mis-match. I can make no guarantees that the application will work with other database versions. Also, I’m sure the developers of Piwigo would prefer thatt users don’t directly change the database. However, in this case, I find it sensible.
It is possible to have duplicate filenames in Picasa with the duplicate filenames being in different directories. The application checks all duplicate filenames (up to 10,000) against the album names. So, even if there are duplicate filenames, it will be ok.