Transcript Computer Vision for Tangible User Interfaces

Computer Vision for
Tangible User Interfaces
Spring 2007
COMP TUI
1
Computer Vision
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Method for extracting information from images and video
streams
Includes object identification and tracking
Commonly combined with video projectors in TUI
applications to augment physical objects with digital
information.
Spring 2007
COMP TUI
2
Computer Vision
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Strengths:
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Fast way to do mockups and prototypes
Can track position and orientation of multiple objects
Weaknesses:
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Spring 2007
Can be sensitive to lighting and obstructions
Not portable
Often not robust
Computationally expensive
COMP TUI
3
Java Media Framework
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A Java library that will interface with most web cams
Makes it easy to capture still frames from a video stream
Sample code available on the compTUI website
http://java.sun.com/products/java-media/jmf/
Spring 2007
COMP TUI
4
ARToolkit
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Open source library
Tracks the position and orientation of physical markers
Real time performance
Markers use simple black squares
Pattern matching allows any marker patterns to be used
http://www.hitl.washington.edu/artoolkit/
Spring 2007
COMP TUI
5
Intel’s Open Source Computer
Vision Library (opencv)
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Real time computer vision library
Open source
Object Identification
Face Recognition
Gesture Recognition
Motion Tracking
Tracks the position and orientation of physical markers
Real time performance
http://www.intel.com/technology/computing/opencv/
Spring 2007
COMP TUI
6
TopCodes
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Tangible Object Placement Codes
Designed for fast and accurate computer vision
Each TopCode encodes a 13-bit number
Can track position, size, and angular orientation of multiple objects
Self-calibrating
100% Java
Code available on the compTUI website
Spring 2007
COMP TUI
7