Name: Alam Shah

ID:10-17685-3

Course Instructor:

KHAN, MD. AL-FARABI

Computer Vision for Interactive

Computer Graphics

A thesis work done by the

authors-

M. Roth, K. Tanaka, C.

Weissman, W. Yerazunis

TR99-02 January 1999

What is computer Vision?

Computer vision is a field that includes

methods for acquiring, processing,

analyzing and understanding images and

high-dimensional data from the real world

in order to produce numerical or symbolic

information

Why we use computer Vision?

• Human-computer interaction

• Computers interpret user movements, gestures

and glances via fundamental visual algorithms.

• Visual algorithms: tracking, shape recognition

and motion analysis

• Interactive apps : response time is fast,

algorithms work for different subject and

environment and economical.

Tracking Objects

• Different methods and techniques are

used to track objects from the real world

• Interactive applications can track two

types of objects –

1. Large objects

2. Small objects

Large Object Tracking

• Large objects like

hand or body tracked.

• Object is in front of

camera.

• Image properties

(Image moments),

and artificial retina

chip do the trick.

Small Object Tracking

• Large objects tracking

techniques not

adequate.

• Track small objects

through template

based technique –

normalized correlation

Normalized Correlation

• Examine the fit of an object template to every position in the analyzed image.

• The Location of maximum correlation gives the position of the candidate hand.

• The value of that correlation indicates how likely the image region is to be a hand.

Example : Television Remote

• To turn on the television, the user holds up his hand.

• A graphical hand icon with sliders and buttons appears on the graphics display.

• Move hand to control the hand icon

Conclusion

• Simple vision algorithms with restrictive

interactivity allows human-computer

interaction possible.

• Advances in algorithms and availability of

low-cost hardware will make interactive

human-computer interactions possible in

everyday life.

References[1] R. Bajcsy. Active perception. IEEE Proceedings, 76(8):996-1006, 1988.

[2] A. Blake and M. Isard. 3D position, attitude and shape input using video tracking of hands and lips. In Proc. SIGGRAPH 94,pages 185{192, 1994. In Computer Graphics, Annual Conference Series.

[3] T. Darrell, P. Maes, B. Blumberg, and A. P.Pentland. Situated vision and behavior for interactive environments. Technical Report 261, M.I.T. Media Laboratory, Perceptual Computing Group, 20 Ames St., Cambridge, MA 02139, 1994.

[4] I. Essa, editor. International Workshop on Automatic Face- and Gesture-Recognition.IEEE Computer Society, Killington, Vermont, 1997.

[5] W. T. Freeman and M. Roth. Orientation histograms for hand gesture recognition. In M. Bichsel, editor, Intl. Workshop on automatic face and gesture-recognition, Zurich, Switzerland, 1995. Dept. of Computer Science, University of Zurich, CH-8057.

[6] W. T. Freeman and C. Weissman. Television control by hand gestures. In M. Bichsel, editor, Intl. Workshop on automatic face and gesture recognition, Zurich, Switzerland, 1995. Dept. of Computer Science, University of Zurich, CH-8057.

End of the Presentation

Thank You