Abstract : Using tiled monitors to build wall-sized displays has multiple advantages: higher pixel density, simpler setup and easier calibration. However, the resulting display walls suffer from the visual discontinuity caused by the bezels that frame each monitor. To avoid introducing distortion, the image has to be rendered as if some pixels were drawn behind the bezels. In turn, this raises the issue that a non-negligible part of the rendered image, that might contain important information, is visually occluded. We propose to draw upon the analogy to french windows that is often used to describe this approach, and make the display really behave as if the visualization were observed through a french window. We present and evaluate two interaction techniques that let users reveal content hidden behind bezels. ePan enables users to offset the entire image through explicit touch gestures. GridScape adopts a more implicit approach: it makes the grid formed by bezels act like a true french window using head tracking to simulate motion parallax, adapting to users' physical movements in front of the display. The two techniques work for both single- and multiple-user contexts.
