Picasa 3 For Linux VERIFIED
Picasa uses picasa.ini files to keep track of keywords for each image. In addition to this, Picasa attaches IPTC Information Interchange Model (IPTC) keyword data to JPEG files, but not to any other file format. Keywords attached to JPEG files in Picasa can be read by other image library software like Adobe Photoshop Album, Adobe Bridge, Adobe Photoshop Lightroom, digiKam, Aperture, and iPhoto.
Picasa 3 for Linux
In Picasa 2 and earlier versions, changes to pictures made in Picasa overwrite the original file, but a backup version of the original is saved in a hidden folder named "Originals" in the same folder as the original picture (.picasaoriginals on Mac OS X).
In Picasa 3, changes to pictures made in Picasa are saved to a hidden file picasa.ini in the same folder as the original picture. This allows multiple edits to be performed without altering the original image. Viewing the picture in Picasa or using the Picasa Photo Viewer will apply modifications on the fly, whereas viewing through other programs (such as Windows XP's Photo and Fax Viewer) will display the original image. Changes can also be made permanent using the "Save" function, where the original file is backed up in a hidden folder .picasaoriginals located in the same folder as the original picture and the modified version is written in its place.
The general idea is this: find all files named .picasa.ini in the tree. For each one, look in its directory to see if there are any other files. If there aren't, remove the directory. (The double quotes around $dir will remove directories that contain spaces.) Otherwise move on.
Picasa is developed as an cross-platform application which is available on Mac, Linux and Windows operating systems. Check the below link and follow it to get your corresponding Picasa. Note that Picasa for linux is out-dated and the latest version of Picasa 3.9 which is released just a day back is not supported for linux. Get Picasa here.