Paper Reading #3: LightGuide: Projected Visualizations for Hand Movement Guidance

Paper Reading #3: LightGuide: Projected Visualizations for Hand Movement Guidance

Intro:

• Title - LightGuide: Projected Visualizations for Hand Movement Guidance
• Reference Information - 
  
  

  Session: Curves & Mirages: Gestures & Interaction with Nonplanar Surfaces
  May 5–10, 2012, Austin, Texas, USA
  
  
  Author Keywords
  On-demand interfaces; on-body computing; appropriated surfaces; tracking; spatial augmented reality;
  ACM Classification Keywords
  H.5.2 [Information interfaces and presentation]: User Interfaces - Input devices & strategies; 
  
  
• Author Bios - Rajinder Sodhi, Hrvoje Benko, Andrew D. Wilson 

Hrvoje Benko

Hrvoje Benko - He is a researcher in Natural Interaction Research group at Microsoft Research. His research is on novel surface computing technologies and their impact on human-computer interaction. Prior to working at Microsoft, he received his PhD at Columbia University, working on augmented reality projects that combine immersive experiences with interactive tabletops. His projects explore the space where the flat digital world of surface computing meets the curved, physical, 3D space we live in.

Andrew D. Wilson - Also works at Microsoft Research. He has an impressive 55 publications (1,034 citations) from 1995-2012, so is the veteran of the team.  

Rajinder Sodhi - He is a PhD student in Computer Science at the University of Illinois. He works at the intersection of computer vision and human computer interaction and is advised by David Forsyth and Brian Bailey. His research focuses on new display and interaction techniques - especially those that allow people to embed interactivity in all aspects of the environment.

Summary:

LightGuide is a system that uses a projection of hints on a person's body to aid in gesture guidance. These projected hints guide the user in completing the desired motion with their body part which is particularly useful for performing movements that require accuracy and proper technique, such as during exercise or physical therapy. This was done with a low cost depth camera and a projector to display the informational interaction techniques. They then quantified the performance of LightGuide with a user study comparing the use of LightGuide to traditional gesture guide videos. Movements were an astounding 85% more accurate with the use of LightGuide aiding the user.

Related work not referenced in the paper:

1. Computer-based training in two-dimensional echocardiography using an echocardiography simulator - 
2. Michael Weidenbach,  
3. Florentine Wild, 
4. Kathrin Scheer, 
5. Gerhard Muth
6. , 
7. Stefan Kreutter, 
8. Gernoth Grunst, 
9. Thomas Berlage, 
10. Peter Schneider
11. OmniTouch: wearable multitouch interaction everywhere - Chris Harrison, Hrvoje Benko, Andrew Wilson
12. Simulating educational physical experiments in augmented reality - Hannes Kaufmann, Bernd Meyer
13. AUGMENTED REALITY PLATFORMS FOR VIRTUAL FITTING ROOMS - Ioannis Pachoulakis and Kostas Kapetanakis
14. Pfinder: real-time tracking of the human body - Wren, C.R. ;  Darrell, T. ;  Pentland, A.P.
15. Spatially Augmented Reality - Ramesh Raskar, Greg Welch, Henry Fuchs
16. Augmented reality visualization for laparoscopic surgery - Henry Fuchs, Mark A. Livingston, Ramesh Raskar, D’nardo Colucci, Kurtis Keller, Andrei State, Jessica R. Crawford, Paul Rademacher, Samuel H. Drake and Anthony A. Meyer
17. Combining multiple depth cameras and projectors for interactions on, above and between surfaces - Andrew Wilson, Hrvoje Benko
18. A Survey of Augmented Reality - Ronald T. Azuma
19. The Everywhere Displays Projector: A Device to Create Ubiquitous Graphical Interfaces - Claudio Pinhanez

The work of this project is in 4 main areas: computer-aided task guidance, task-guidance in augmented reality, augmenting environments with projectors, and projection-based guidance. LightGuide bases off of related work in these areas, such as Feiner et. al using augmented reality to help with laser printer assembly, or support systems for playing guitar or manufacturing. These involved cumbersome head units or other user attachments. There is past work with depth sensing cameras and stationary projectors like LightGuide as well though. There is also former projection-based guidance systems that have been implemented, like LightGuide. LightGuide is different though, because it provides the hints with real-time feedback directly on the user's hand that is tracked in mid-air for guidance. So, LightGuide is novel in the sense that it combines all these features in a way that has not been done before. It provides dynamic feedback, is mid-air and free, and is with a depth camera and projector. The authors appropriately talked about all the other related works and also explained why the aforementioned reasons made theirs unique.

Evaluation:

The authors evaluated their work by running a test on 10 users. The test was to see if the system worked better than the typical gesture guidance system of watching a how to video. The test participants had to trace 5 paths: a line, a square, a circle, the letter 'N", and a line plus curve, all run at different depths to ensure adequately tested variety of depths. Each participant did 90 trials (6 conditions x 5 paths x and 3 angles), which gave quantitative data on how accurately the user followed the given path by time, position, and hand-orientation (quantitative, objective). The users were also interviews after each session and after the complete study to get their opinion on the different methods of hints and the overall effectiveness of the system (qualitative, subjective). This study measure the system as a whole and was very complete and thorough in its evaluation.

Error Report by Guidance System

Discussion:

I think that the LightGuide is an interesting project. I understand that it has some possible uses, but I think it still very early in its progress. There was no real-life demo available, just proposed uses. Of these, I think physical therapy the most probable future use. I think the evaluation was appropriate and covered the system quite completely. It got both numbers and opinions on the device to get a full evaluation. I think the contribution is not necessarily novel, but a nice improvement on other systems. The real-time feedback in the LightGuide is what really sets it apart, and I think it has a chance to become something useful in the future.