Publications
There are more details on my Google Scholar page.Patents
Sharing Data Between Multiple Programs for Collaboration
GB 2479617 (A),
published 2011-10-19. Storing structured data in a client-server system for synchronous remote collaboration.
Projected Image Correction System and Correction Information Generation Program
WO 2007139189 (A1), published 2007-12-06. Photometric characterisation and compensation for digital projectors.
Refereed publications
Some Practical Issues with Touch-Based Interfaces
Mark Ashdown, short paper in
D-CIS Lab Multitouch Workshop, due in November 2010.
High-Resolution Interactive Displays
Mark Ashdown,
Philip Tuddenham, and
Peter Robinson,
a chapter in
Tabletops - Horizontal Interactive Displays, Springer,
due in April 2010.
Bibtex
Effect of Workspace Awareness Support on
Distributed Team Collaboration
Mark Ashdown and
Yale Song, a poster at
Tabletop 2009,
Banff, Canada, November 2009.
Paper
Poster
Bibtex
Awareness in Synchronous Collaboration between Tabletop and Handheld Displays
Mark Ashdown, a poster at
Tabletop 2008,
Amsterdam, Netherlands, October 2008.
Paper
Poster
Bibtex
Designing Tabletop Interfaces for Asymmetric Distributed Collaboration
Mark Ashdown and
Stacey D. Scott, a poster at
Tabletop 2007,
Newport, Rhode Island, USA, October 2007.
Paper
Poster
Bibtex
Asymmetric Synchronous Collaboration Within Distributed Teams
Mark Ashdown and
Mary Cummings,
7th International Conference on Engineering Psychology and Cognitive Ergonomics at
HCII 2007,
Beijing, China, July 2007. Published in Springer Lecture Notes in Artifical Intellgence,
LNAI 4562, ISBN 978-3-540-73330-0, pages 245-255.
Paper
Bibtex
Perceptual Photometric Compensation for Projected Images
Mark Ashdown,
Imari Sato,
Takahiro Okabe, and
Yoichi Sato,
IEICE Transactions on Information Systems J90-D, 8, pages 2115-2125.
This is a journal article based on the
paper in MIRU 2006.
Note: this paper is in Japanese, and requires extra fonts to view the PDF.
Paper
Bibtex
Perceptual Photometric Compensation for Projected Images
Mark Ashdown,
Imari Sato,
Takahiro Okabe, and
Yoichi Sato,
Meeting on Image Recognition and Understanding MIRU 2006 (the main Japanese domestic computer vision conference),
Sendai, 19-21 July 2006.
Selected as runner-up for the best paper award
(There was one best paper, and three runners-up).
Note: this paper is in Japanese.
Paper
Bibtex
Robust Content-Dependent Photometric Projector Compensation
Mark Ashdown,
Takahiro Okabe,
Imari Sato, and
Yoichi Sato,
Third IEEE International Workshop on Projector-Camera Systems
(PROCAMS 2006),
New York City, 17 June 2006, in conjunction with the
IEEE Computer Society International Conference on Computer Vision and Pattern Recognition (CVPR 2006).
Winner of the best paper award.
Paper
Slides
Bibtex
Escritoire: A Personal Projected Display
Mark Ashdown and
Peter Robinson,
IEEE Multimedia Magazine,
Volume 12 Number 1, January-March 2005, pages 34-42.
Acceptance ratio approximately 25%.
Article
Bibtex
Remote Collaboration on Desk-Sized Displays
Mark Ashdown and
Peter Robinson,
Computer Animation and Virtual Worlds,
Volume 16 Number 1, February 2005, pages 41-51.
We argue that a task space is more important than a person space
for many types of remote collboration. We describe the Escritoire desk
display system, the software architecture that allows multiple desks to
be connected, and user trials we conducted. Participants could use the
system for remote collaboration with a minimum of training, and found
pen traces useful for gesturing to each other.
Article
Bibtex
Steerable Projector Calibration
Mark Ashdown and
Yoichi Sato,
Second IEEE International Workshop on Projector-Camera Systems
(PROCAMS 2005),
San Diego, California, USA, 25 June 2005, in conjunction with the
IEEE Computer Society International Conference on Computer Vision and Pattern Recognition (CVPR 2005).
Note: Equation 6 in this paper is wrong - the denominator of the fraction
can be discarded, and d_2 should be changed to d_i.
It would probably be better to do the least-squares
optimization for that part of the algorithm in a different way.
Paper
Slides
Bibtex
Combining Head Tracking and Mouse Input for a GUI on Multiple Monitors
Mark Ashdown,
Kenji Oka, and
Yoichi Sato,
CHI 2005 Extended Abstracts,
Portland Oregon, USA, 2-7 April 2005. Acceptance ratio 40%.
Paper
Video (8.5 MB AVI file, MPEG4 video)
Bibtex
Attentive Interfaces for Multiple Monitors
Mark Ashdown and
Yoichi Sato,
CHI 2005 Workshop on Distributed Display Environments,
Portland Oregon, USA, 3 April 2005.
Paper
Bibtex
A Personal Projected Display
Mark Ashdown and
Peter Robinson,
ACM Multimedia 2004 video demonstration. Acceptance ratio under 50%
A 7 minute video showing the Escritoire in use.
Video (17 MB AVI file, DivX)
Abstract
Bibtex
Personal Projected Displays
Mark Ashdown, PhD thesis,
University of Cambridge Computer Laboratory,
submitted September 2003.
Available as
Technical Report
UCAM-CL-TR-585, March 2004.
I have used the technological advances in large display devices, the lack of
space in conventional interfaces, the proved manual and cognitive benefits of
alternative input systems, and the sparsity of effective real-time remote
collaboration systems to motivate the development of a desk-based interface
that I call the Escritoire. Overlapping projectors create a display that
fills a desk and also has a high resolution region for detailed work, two
pens provide bimanual input over the entire area, and an interface like
physical paper addresses some of the affordances not provided by the
conventional user interface. Multiple desks can be connected to allow remote
collaboration and I report the results of tests with single users and
collaborating pairs.
Report
Bibtex
Intelligent Tutoring and Supervised Problem Solving in the Browser
William Billingsley,
Peter Robinson,
Mark Ashdown, and
Chris Hanson,
IADIS International Conference on WWW/Internet 2004,
Madrid, Spain, 6 - 9 October 2004, pages 806-811.
Paper
Bibtex
Robust Projected Displays for Ubiquitous Computing
Jay W. Summet,
Matthew Flagg,
Mark Ashdown,
Rahul Sukthankar,
James M. Rehg,
Gregory D. Abowd,
Tat Jen Cham,
Workshop
on Ubiquitous Display Environments, Nottingham, England,
7 September 2004, in conjunction with
UbiComp 2004.
A summary of several pieces of work on projected displays.
Paper
Bibtex
A Flexible Projector-Camera System for Multi-Planar Displays
Mark Ashdown,
Matthew Flagg,
Rahul Sukthankar, and
James Rehg,
Proceedings of
IEEE Computer Society Conference on Computer Vision and Pattern Recognition
(CVPR) 2004, Volume 2, Washington D.C., USA, 27 June - 2 July 2004,
pages II-165 - II-172.
Acceptance ratio 29%.
We describe how to create a projected display that spans multiple planar
surfaces using a single projector and camera whose positions and intrinsic
parameters are unknown. We also had a demo at the conference.
This paper is based on the
Intel tech report below.
Paper
Poster
Video (6 MB AVI file)
Bibtex
The Escritoire: Remote Collaboration in a Task Space
Mark Ashdown and
Peter Robinson,
Workshop on Experiential Telepresence,
Berkeley, California, USA, 7 November 2003,
in conjunction with
ACM Multimedia 2003, pages 73-75.
I presented poster at the workshop on the use of the Escritoire for remote collaboration
and the contrast between the task space it provides and the person space of a conventional video-conference.
I also set up a demo of the foveal display using two projectors.
Paper
Poster
Bibtex
Experiences Implementing and Using Personal Projected Displays
Mark Ashdown and Peter Robinson,
IEEE International Workshop on Projector-Camera Systems
(PROCAMS 2003),
Nice, France, 12 October 2003, in conjunction with the
9th International Conference in Computer Vision (ICCV 2003).
Describes the issues I encountered implementing the Escritoire, and
the results of experiments with single users working on their own
and with pairs of users collaborating using separate desks.
Explains the physical hardware configuration, and the use of commodity 3D video
hardware to warp the graphics before projection.
Reports the results of user tests and their implications for the design of personal
projected display systems.
Paper
Bibtex
A Life-Sized Desk Display for Peripheral Awareness and Remote Collaboration
Mark Ashdown and Peter Robinson,
First Research Workshop on Augmented Virtual Reality (AVIR 2003),
Geneva, Switzerland, 18-19 September 2003.
Extended abstract about the Escritoire, particularly covering the interface issues.
Paper
Bibtex
The Escritoire: A personal projected display
Mark Ashdown and
Peter Robinson,
Proceedings of the
11th International Conference in Central Europe
on Computer Graphics, Visualization and Computer Vision (WSCG 2003),
Pilsen, Czech Republic, 3-7 February 2003, pages 33-40. Acceptance ratio 32%.
Program available here.
The Escritoire combines two overlapping projectors to form a
foveal display, allows two pens to be used simultaneously by combining
a high-accuracy digitizer with a low-accuracy ultrasonic pen, and allows
images, documents and conventional computer displays to be arranged and
manipulated on a desk-sized display.
Paper
Bibtex
The Writing's on the Wall: Large, Remotely Controlled Displays
Mark Ashdown and
Peter Robinson,
Proceedings of the
First European Conference on Computer-Supported Collaborative Learning 2001 (Euro-CSCL),
Maastricht, Netherlands, 22-24 March 2001, pages 83-88.
Describes a custom-made projection display with pointing device that can be
used to control standard application programs, and interprets experiences
using it as a demonstration tool.
Paper
Bibtex
Other publications
Escritoire2 Project: Conclusions and Future Work
Mark Ashdown, September 2009. This is the fifth and final deliverable for European Commission FP6 Outgoing International Fellowship 21743.
This a summary of the work completed in Marie Curie Fellowship 21743, and a list of directions for future research. The domain of urban search and rescue was analysed, a system for synchronous remote collaboration was implemented, experiments were performed, and results were produced. Future work is suggested, particularly on the user interface and on networking issues such as quality of service.
Paper
eStrategies Projects article
A feature article and interview in
eStrategies Projects magazine,
July 2009, pages 92-96.
A
digital version of the magazine
is available.
Feature
Interview
User Experiences with Asymmetric Distributed Collaboration
Mark Ashdown, April 2009. This is the fourth deliverable for European Commission FP6 Outgoing International Fellowship 21743.
Description of quantitative and qualitative results from several experiments on the usability of a remote collaboration system. Participants preferred to have workspace awareness support enabled, and it increased the amount of deictic gesturing. Various strategies were used for collaboratively entering reports, and giving directions on the map. Increasing the team size required subordinate personnel to be more autonomous. Participants suggested various enhancements, such as tactile feedback on the handheld device.
Paper
Design of Experiments for Asymmetric Distributed Collaboration
Mark Ashdown, September 2008. This is the third deliverable for European Commission FP6 Outgoing International Fellowship 21743.
Design of an experiment to test a system for synchronous collaboration in distributed teams. Tabletop and hand displays were combined to provide sharing of visual information. Experimental participants were placed in an urban search and rescue scenario. Measures were made of the process of collaboration, the product of the teams' work, and the satisfaction of the team members.
Paper
Implementation of Asymmetric Distributed Collaboration
Mark Ashdown, March 2008.
This is the second deliverable for European Commission FP6 Outgoing International Fellowship 21743, entitled "Distributed Crisis Management using Remote Collaboration Technologies".
A design is presented for a set of interfaces for tabletop and handheld displays that allows maps and schedules to be shared and edited in real-time on various linked devices. Components of the information and events that are transmitted over the network are listed. Also, a 3D world simulation for an urban search and rescue scenario is described.
Paper
Asymmetric Distributed Collaboration in Emergency Response
Mark Ashdown, October 2007.
This is the first deliverable for European Commission FP6 Outgoing International Fellowship 21743, entitled "Distributed Crisis Management using Remote Collaboration Technologies".
The need for synchronous collaboration between the operational and tactical levels in an emergency response organization is used to motivate research on asymmetric collaboration between large displays in a command centre and small ones in the field. A cognitive task analysis is presented that could be used in the design of such a system. The analysis is based on an urban search and rescue scenario.
Paper
A Flexible Projector-Camera System for Multi-Planar Displays
Mark Ashdown,
Matthew Flagg,
Rahul Sukthankar, and
James Rehg,
Intel Research Technical Report IRP-TR-03-14, November 2003.
Extends the work described in HP Labs report HPL-2003-24 listed below.
We use an uncalibrated projector-camera pair to create ad hoc
multi-planar display surfaces.
The calibration robustly calculates homographies from minimal information.
This technique is also explained in the
CVPR 2004 paper above.
Paper
Bibtex
Applications for Multi-Planar Projected Displays
Mark Ashdown,
Matthew Flagg,
Rahul Sukthankar, and
James Rehg,
CVPR 2004 Demo.
Abstract
Robust Calibration of Camera-Projector System for Multi-Planar Displays
Mark Ashdown and
Rahul Sukthankar,
Hewlett Packard Cambridge Research Laboratory,
Technical Report
HPL-2003-24,
2003.
Describes a robust method for calibrating a novel system where a single
projector creates a display that spans multiple planar surfaces. A variant of
structured light is used to find the edges between the surfaces. Robust
methods are described for calculating camera to projector homographies from
lines, and performing metric rectification of the planes by imaging everyday
objects such as postcards. A refined version of this technique is described
in the Intel tech report above.
Report
Bibtex
The Escritoire: A personal projected display for interacting with documents
Mark Ashdown and
Peter Robinson,
University of Cambridge Computer Laboratory,
Technical Report
UCAM-CL-TR-538, June 2002.
Describes the Escritoire's real-time image warping system,
graphical interface, and distributed client-server design.
The WSCG 2003 paper above was based on this report.
Report
Bibtex
Escritoire Poster
Mark Ashdown, 2002. A single-page poster in the
Rainbow Group's
series.
Poster
Large-Format Computer Interfaces
Mark Ashdown,
First Year Ph.D. Report, University of Cambridge, July 2000.
Motivates attention on displays with trends in technology,
reviews visualisation techniques and novel user interfaces, and reports on
current projects dealing with task-centred collaboration. Provides details
of the hardware and software created during the first year of the Ph.D. and
sets out the plan for the subsequent two years.
Report
Vitrigraph: Stained Glass Window Designer
Mark Ashdown,
B.A. project dissertation, University of Cambridge, June 1999.
Explains the design and implementation of Vitrigraph, an application
program that allows a non-technical user to design a detailed window with
intuitive manipulation of graphical components. Novel data structures and
algorithms are used to detect design faults, calculate production costs, and
produce realistic ray-traced images.
Dissertation
Files
Here is a rough collection of images and other files related to my projects. You can browse the files using the links below.
- Escritoire
- Projector calibration/compensation
- Head tracking interface
- Remote collaboration for emergency response
- The Escritoire evolved into a product by Thales called nuVa