Sharing is possible with Fickr, Zenfolio, SmugSmug but not Piwigo: currently I synchronize with a python script using Piwigo APIs but it would be more convenient to do it directly from PSu.
From this old thread ("viewtopic.php?f=57&t=23213&hilit=ipernity") I note Hert comment: "from the next update on, it will be possible to use a script to upload photos"
Could have an already existing script to use as a template to adapt to Piwigo ?