Computer monitor is pretty strict device – is displays information withing its frame. Outside and behind its dark. To change that Sebastien has been working on several versions of SlightBox projects where it allows playing light effects behind screen that extends on-screen effects and somewhat removes limits between screen and outside world.
Video demonstration speaks for itself. Watching movies and playing games become different with those effects. The heart of this system is Raspberry Pi which does video signal analysis and determines color pixels from captured frames. Python script uses OpenCV library to do this task. Once color data is gathered, it is sent over SPI to LPD8806 LEDs behind screen. Since analyzing HDMI signals is quite tricky, he split HDMI signal where one was converted to S-video which then was fed to Raspberry Pi with STK1160 adapter. Raspberry pi also has a standard LCD for fast control and monitoring parameters. Infrared channel allows remote control of SlightBox. Raspberry Pi also allows configuring devices via web interface. So this is fun device that vivid and extend any HDMI screen at your house. Fun guaranteed. (translated source)