Survey of Pen-and-Paper Computing - Human-Computer Interaction - page 63

Fig. 2.25 PaperLens offers tangible views for information visualization above interactive tabletops
(photo courtesy of Raimund Dachselt)
A very influential system is PaperWindows [40]. It introduces thin and lightweight
paper displays as an interface for the windows of the operating system. Using a
camera-projection unit, PaperWindows displays the contents of each GUI window
onto one sheet of paper that the user can freely move on the desk. The authors
present a set of interactions for copying windows from the computer to paper and
back, for navigating through contents on the paper displays, for copy&paste of con-
tents, and for annotating contents. These gestures leverage not only pen and touch
input, but introduce paper manipulations, such as flipping or stacking pages, as a
means for controlling the system.
PaperLens [142] (Fig. 2.25) is a tangible view for information visualization. A
passive paper display can be used as an interactive lens for data that is displayed
on an interactive tabletop. This is similar to the Interaction Lens of the A-Book
(introduced above), but the PaperLens can be freely moved and rotated in three
dimensions above the tabletop display. This allows for a set of novel interactions
and visualizations that take into account not only the lens' position on the tabletop,
but also its distance from the table surface and its 3D orientation.
The concepts discussed above use paper sheets of a fix size. One advantage of
paper is that it can be modified in shape and size, for instance by folding. Lee et
al. [70] examine different form factors of paper displays that allow for resizing the
display. They present a large rectangular display that can be folded, a scroll that can
be rolled in an out, as well as form factors for resizable displays which are inspired
by fans and umbrellas. Inspired by this work, Xpaaand [56] addresses interaction
techniques for such resizable displays. The authors present a hardware prototype of
a passive rollable display and introduce a set of interaction techniques for manipu-
lating digital information by resizing the display.