Revision as of 11:49, 2 February 2007

Accessing the KDE-menu using the system (2.72 MByte video)

Developed by Juan Roldan, ERASMUS exchange student from Cordoba, Spain

Ushakiran Soutapalli, MSc student at Sheffield Hallam worked on the graphical user-interface

Camera-Projector System

Application

A software for camera-projector interaction was developed by Juan Roldan, Ushakiran Soutapalli, Julien Faucher, and Jan Wedekind at the Microsystem & Machine Vision Laboratory (MMVL) at Sheffield Hallam University, UK.

The software makes use of a low cost off-the shelf webcam that is calibrated against a standard projector screen. The webcam is used to determine the position of physical pointer (e.g. a pen) which is then used to virtually move the X11 pointer. Point-and-click functionality has also been implemented.

The vision system uses the Mimas real-time computer vision toolkit developed by the MMVL.

How it works

Detection

The detection is a simple colour-segmentation using a thresholded colour-histogram. Therefore you need to use a marker pen or some other object with a distinct colour. The colour should not appear on the screen itself. If the colour of the pen will change due to different illumination conditions, you need to capture these colours when taking the reference image.

Mouse clicks

The standard deviation of a few recent mouse-positions is used as a criterion, wether the mouse is stationary or moving. If the mouse is stationary, a mouse click is issued.

Design

UML-diagram of static structure

UML-diagram showing collaboration of classes

Changelog

2007-02-02 Jan Wedekind <jan at wedesoft.de> 1.0

• Applications seems to run stable now -> releasing version 1.0

2006-10-20 Jan Wedekind 0.6

• Minor fixes on configure-script

2006-10-20 Jan Wedekind 0.5

• Fixed the check for gfortran (using AC_PROG_FC now). Thanks to Steven G. Johnson!

# On the older Mandriva version you may have to configure using
./configure FLIBS="-lgfortran"

# On openSuSE 10.0 libgfortranbegin.a was compiled without "-fPIC". You need to configure using
./configure F77=gfortran FLIBS="-lgfortran"

2006-10-17 Jan Wedekind 0.4

• Added support for UYVY-cameras.

2006-10-16 Jan Wedekind 0.3

• Video display can be zoomed using the mouse-wheel.
• Display error-messages when accessing camera fails.

2006-10-13 Jan Wedekind 0.2

• Removed dependency on ImageMagick.

Downloads

Download mando-1.0.tar.bz2 (334 kByte). For your convenience the required parts of Mimas are included in the package. To build and run the package do

tar xjf mando-1.0.tar.bz2
cd mando-1.0
./configure
make
./mando

Gallery

Artist's impression of the system	Interactive camera-projector system	Long demonstration of the prototype-system (11.4 MByte video)	Short interactive slides presentation with the system (6.3 MByte video)	Browsing the file-system and trying to play minigolf (14.4 MByte video)
Playing Reversi against the computer (5.54 MByte video also available at video.google.co.uk)	Calibration of the screen using projected patterns	Prototype of early user-interface (13.7 MByte video)	Screenshot of the wizard for configuring the recognition algorithm

See Also

• Mimas Camera Calibration
• Student Projects Available

External Links

• Interative Camera-Projector System
  • Project page at KDE-apps
  • The interactive camera-projector system at google video
• References
  • A Flexible New Technique for Camera Calibration: Zhengyou Zhang
  • Creating input events in Linux/X11 using the X11 test interface
  • Report by Ushakiran Soutapalli
• Other projects
  • Edward Tse - Interactions Inventor
  • Multi-Touch Interaction Research
  • Magic board project by IIHM
  • IBM Research on interactive projector
  • Finger tracking with laser scanner
  • LaserGo allows playing Go using a laser-pointer
  • E-Chalk project
  • MIT iCampus: Magic Paper