virtual reality 3d home applications
DESCRIPTION
Presentation about one 3D home applications based on the autostereoscopic technology involving lenticular lenses and 2DplusDepth contentTRANSCRIPT
![Page 1: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/1.jpg)
3D Home Technology
![Page 2: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/2.jpg)
Introduction
Capturing 3D scenery
Processing the captured data
Displaying the results for 3D viewing
Conclusion
![Page 3: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/3.jpg)
Several fields in auto- stereoscopic 3D Home technology :
3D home projectors 3D TV 3D computers screens 3d mobile phones...
![Page 4: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/4.jpg)
Focus on the 3D TV for this presentation.
More precisely on one kind of 3D TV using lenticular lenses:
Phillips WOW auto-stereoscopic 3D display products
![Page 5: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/5.jpg)
Two main approches :
Use multiple traditional cameras
One video associated to a per-pixel depth map
![Page 6: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/6.jpg)
Objective : recording the same scene form different points of views.
![Page 7: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/7.jpg)
Advantage :▪ providing exact views for each eye
Disadvantage :▪ can be optimized only for one receiver configuration
(size and number of views of the display)▪ the amount of data necessary to transmit the
information of the two monoscopic color video is quite important.
![Page 8: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/8.jpg)
Objective : using only a 2D picture/video associated to a map representing the depth of the scene.
![Page 9: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/9.jpg)
Advantage:▪ Don’t need a geometric model of the
model/environement▪ Can be done proportionally to screen size.
Disadvantage:▪ Visual artefacts are created during the warping.
![Page 10: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/10.jpg)
![Page 11: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/11.jpg)
Depth-image-based rendering (DIBR)
Techniques to allow depth perception from a monoscopic video + per-pixel depth information.
Create one or more “virtual” views of the 3D scene.
![Page 12: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/12.jpg)
![Page 13: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/13.jpg)
3D Image Warping : “warp” the pixels of the image so they appear in the correct place for a new viewpoint.
Creation of 2 virtual views :
![Page 14: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/14.jpg)
Pinhole camera model : define a mapping from image to rays in space (one center of projection)
Each image-space point can be placed into one-to-one correspondence with a ray that originates from the Euclidean-space origin.
![Page 15: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/15.jpg)
This mapping function from image-space coordinates to rays can be described with a linear system:
![Page 16: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/16.jpg)
![Page 17: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/17.jpg)
Two different centers of projection (C1 and C2) linked by rays to one point X.
![Page 18: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/18.jpg)
Form the right image : X1 determine a ray d1 via the pinhole camera maping with
From the left image we have :
Therefore the coordinate of the point X can be expressed as :
Where t1 and t2 are unknown scaling factors for the vector from the origin to the viewing point which make it coincident with the point X.
![Page 19: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/19.jpg)
t2/t1 = 1 :
McMillan & Bishop Warping Equation :
Per-pixel distance values are used to warp pixels to the proper locationdeppending on the curent eye postion.
![Page 20: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/20.jpg)
![Page 21: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/21.jpg)
Main problem of warping : the horizontal changes in the death map reveals aeras that are occluded in the original view and become visible in some virtual views.
To resolve this problem, filters and extrapolation techniques are used to fill this occlusions.
In pink : the newly exposed aerascorresponding to the new virtual camera
![Page 22: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/22.jpg)
Some examples of pre-processing for the depth map:
Smoothing of Depth Map: To reduce the holes, smoothing the depth map with smooth filters like
average filters or Gaussian filters. They remove the sharp dicontinuities from depth image.
Reshaping the dynamic range of the Depth Map: Expands dynamic range of higher depth values and compress lower
ones improve the rendering quality.
![Page 23: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/23.jpg)
Butterflies 2D plus depth
Butterflies 3D
AI broken 2D plus depth
![Page 24: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/24.jpg)
lenticular lenses
Basics for 3D viewing : two images, one for the left and one for the right eye.
lenticular lenses technology :
The both images are projected in different direction, so each one is correpondign to one eye.
![Page 25: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/25.jpg)
The lenses array generates a parallax difference
Series of viewing spots with transitions
![Page 26: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/26.jpg)
The technology presented before is one of the most developped for the 3D home technology and is predicted to become accessible to the public in the next years.
The capturing and processing techniques used are flexible to fit with the display receiver.
Any 2D scene can be converted in a 3D display.
![Page 27: Virtual Reality 3D home applications](https://reader033.vdocuments.mx/reader033/viewer/2022061219/54b9b6994a7959ca2f8b459a/html5/thumbnails/27.jpg)
Sources :
SIGGRAPH ’99 course notes by Leonard McMillan A 3D-TV Approach Using Depth-Image-Based Rendering (DIBR) by CHRISTOPH
FEHN Distance Dependent Depth Filtering in 3D Warping
for 3DTV by Ismaäel Daribo, Christophe Tillier and Beatrice Pesquet-Popescu
Questions ?