Paper Reading #22

Mid-air pan-and-zoom on wall-sized displays

Authors:
Mathieu Nancel - Univ. Paris-Sud & CNRS; INRIA, Orsay, France
Julie Wagner - INRIA; Univ. Paris-Sud & CNRS, Orsay, France
Emmanuel Pietriga - INRIA; Univ. Paris-Sud & CNRS, Orsay, France
Olivier Chapuis - Univ. Paris-Sud & CNRS; INRIA, Orsay, France
Wendy Mackay - INRIA; Univ. Paris-Sud & CNRS, Orsay, France

Proceeding CHI '11 Proceedings of the 2011 annual conference on Human factors in computing systems

Summary
Extremely large data sets are difficult to visualize. For example, the Spitzer's 4.7 billion pixel image of our galaxy can be visualized on multiple displays in different ways, but some are better than others. A user can sit at a desk in front of the wall-sized display and use physical input such as a mouse to manipulate the images, or use mid-air gestures in 1,2, or 3 dimensions.

Hypothesis
H1: Two handed gestures should be faster than one handed gestures.
H2: Two handed gestures should be easier and more accurate.
H3: Linear gestures for zooming should be better for zooming but eventually will be slower than circular gestures due to repositioning.
H4: Users will prefer gestures that do not require repositioning.
H5: Gestures using small muscles will be faster than larger ones.
H6: 1D-path gesures should be the fastest.
H7: 3D-free gestures will be more tiring.

Methods
There are several design factors to be determined. The user can use one or both hands for input. Using one hand allows the other hand to perform other actions, but using two hands can allow panning and zooming to be done at the same time. Gestures can be linear or circular. Linear gestures (moving a slider) are naturally mapped, but may require clutching. Circular gestures do not require clutching, but is not natural. Different degrees of freedom have different advantages as well. 1D path gestures have strong haptic feedback but are limited in dimension. 2D surface has more freedom but has less feedback. 3D free hand gestures have the most freedom, and does not require any device. The only issue is that there is no feedback at all.



Results
Two handed gestures were found to be faster than one hand gestures. One dimensional path gestures were the fastest of all the gestures as well. Even though for circular gestures, the participants did not have to move back to reposition, the linear gestures were faster because of less overshoot. The participants favored the faster gestures because they were the easiest.

Conclusion
There exists 3D stylus devices for 3D drawing programs. I can imagine these devices could be modified to allow better haptic feedback with servos and strain sensors to allow much better feedback. A more interesting task would be to allow for 3D-free manipulation of virtually projected 3D images. There exist several engineering problems to solve this issue however. Back to the display of large data sets, I don't think too many people will benefit directly from being able to see 100 million pixels at home.