Media Lab Europe
Human Connectedness research group


a layered video manuscript of social interaction

Ben Piper, Stefan Agamanolis

A palimpsest is a manuscript consisting of a later writing superimposed upon an original writing. This word has been borrowed for the title of this project that aims to superimpose layers of recorded social interaction and present them as a single image. In contrast to conferencing tools and portals that enable chance encounters between distant locations, the Palimpsest facilitates chance encounters between different points in time.

The Palimpsest installation consists of a rear-projection screen and camera aimed across an interaction area, which could be a hallway or passage inside a building, or a special area dedicated to the installation. A computer digitizes camera images and controls the projected video display. Images of passers-by or participants entering the interaction area are extracted from the background using an in-house segmentation algorithm. These extracted images are then layered into a video loop that repeats itself every several seconds.

Because the video is looped, if a passer-by lingers in the space, she will see a delayed copy of herself entering the space from several seconds ago, and even more layers if she remains longer, together with the layers generated by other passers-by from earlier points in time. These layers accrue on the screen over several minutes, hours, even days, creating a unique visual that collapses time and compresses the recent social goings-on of the given space.

Palimpsest might be thought of as capturing and conveying the intersections of mobile humans with a particular point in space over an extended period of time. Increasing the persistence of these intersections raises awareness of the social history of a place and allows the viewer to witness the human crowd that has passed through a seemingly quiet and empty space. Even if totally alone, a passer-by is able to "transcend time" and become a part of this community, and to interact with its members (including oneself!).

The Palimpsest architecture also offers new artistic possibilities, particularly with improvisational theater. Future directions on this thread include control over the length and appearance of each video layer and the addition of audio to the system.

Publications and Links

  • An early Palimpsest demo movie made by Ben Piper.

  • Another Palimpsest demo movie.

  • Palimpsest was exhibited at the Darklight Film Festival, Dublin, 20 - 22 September 2002.

  • Palimpsest was exhibited at Collision 3 at the MIT Museum, Cambridge, Massachusetts, USA, 31 May - 2 June 2002. Ben produced a video about this show.

    Palimpsest is discussed in:

    • Stefan Agamanolis, Designing Displays for Human Connectedness (book chapter), in Kenton O'Hara, Mark Perry, Elizabeth Churchill, and Daniel Russell (eds), Public and Situated Displays: Social and interactional aspects of shared display technologies, Kluwer, 2003. (PDF)