Web Tracker

Attach:webtracker-1.png WebTracker lets people create a visual history of custom notifications to track personally meaningful changes to web pages. Notifications are assembled as a collage of regions extracted from the fully rendered (bitmap) representation of the web pages. They are triggered when visual changes between successive visits are detected within regions. To use the system, a person specifies a notification by clipping personally interesting regions from the bitmap representation of a web page and reformatting them into a small collage. The person then specifies regions on the page that will be monitored and compared for visual differ-ences over time. The system automatically generates a notification (the collage plus a title and timestamp) when differences are detected. Finally, the person views the generated notifications in several ways: as only the most recently changed version (to illustrate current state), or as an image history that can be individually browsed or played back as a continuous video stream.

Creators: Saul Greenberg and Michael Boyle,


Download and Installation

Different versions are dates.

  • December 12, 2005. <Under construction>

Recipes and How-To's

  • (Under Construction)

Tutorials and Examples

  • (Under Construction)


  • Academic paper by Greenberg and Boyle describes a slightly earlier version of this system (a more recent paper in submission is available from the authors).