2. Agenda
1) What is Augmented Reality?
2) Augmented Reality vsVirtual Reality.
3) AR System.
4) Requirements.
5) Types ofAugmented Reality.
6) Key issues ofAR.
7) Applications ofAR.
3. What is Augmented Reality?
Combination of two environments
i. the real environment viewed by the user.
ii. a virtual environment generated by the computer.
+ =
4. Term “Augmented Reality”
Real environment is augmented by means of virtual objects
Supplements reality, instead of completely replacing it
Image-enhanced by
inserting additional information.
removing the unnecessary region.
Why research this?
Enhances person’s perception.
Enhances person’s performance.
Provides a user with
work efficiency, convenience, interesting effects, and information in industry,
education, entertainment, etc.
Virtual Reality
6. Augumented Reality vsVirtual Reality
Virtual Reality Augmented Reality
A user is fully immersed inVirtual Reality. Inserting virtual objects into real environment.
8. AR System
Requirements of AR system
Blending real and virtual
Real-time interaction
Registration between 3D and 2D
Portability for wearable AR
Non-AR system:
Composition in film (ex. “Jurassic Park”)
Photorealistic virtual object
But not interactive media
2D virtual overlay (ex. “captions inTV”)
Interactive in real-time
But not combined with the real world in 3D
10. Types of Augmented Reality
Device-basedAR:
Uses hardware equipment.
Acquiring position data from position tracker, magnetic sensors,GPS, etc.
Including the camera(s).
Vision-BasedAR:
Only uses a camera or multiple cameras
Estimating user’s position from input images
11. Device based AR:
Architecture andWorking of Device based AR:
Image Capture
Camera Frame
Grabber
Display-Out
Monitor or HMD
AR Processing
Synthesis
Virtual Object
Rendering
Position
calculation
Data acquisition
Measuring instruments
12. Vision based AR:
Architecture andWorking ofVision based AR:
Display-Out AR Processing
Image Capture
Camera Frame
Grabber
Feature extraction
& tracking
Monitor or HMD
Synthesis
Virtual Object
Rendering
Camera
Calibration
Buffer
13. Key technical issues in AR
3D Modeling
generates a virtual object to be inserted
Display device
displays mixed scenes with real and virtual environments
Calibration
estimates camera parameters
calculates transform between real and virtual world coordinates
Tracking
detects user’s position and orientation
chases feature points for vision based tracking
Registration
merges a virtual object into real environment exactly
14. 3D Modelling
3D model design tools
ex) Mayatm, SoftImagetm, …
3D reconstruction from images
Range Finder (Laser scanner)
15. Display Devices
Optical see-through Head Mounted Device(HMD)
Micro optic Head Mounted Device (HMD)
16. Calibration
Calculate the camera’s parameters
intrinsic(focal length, principal points, axes’ scale/skew) and extrinsic(position, direction)
parameters
Camera CalibrationToolbox for Matlab
http://www.vision.caltech.edu/bouguetj/calib_doc/
17. Tracking & Registration
Tracking
Report the locations and orientations of the user and the surrounding objects in the
environment.
continually matched with the user’s real-world and
the computer generated virtual-world.
Registration
Virtual and real worlds must be properly aligned.
If not
compromises illusion that the two coexist
prevents acceptance of many applications