Augmented
Reality
Reconstructing Trajectory
of Camera for Special Effects
It is increasingly common
to encounter situations where live action material supplied from film or
video and a set of computer graphics models are to appear seamlessly in
the given sequence. In the case of a fixed camera or simple linear movements,
common compositing techniques are sufficient to fit in the models. However,
if the camera undergoes some complicated motion path in 3D space, then
adaptation by hand to ensure perspectively correct alignment of the computer
graphics models would take a lot of time, if it can be done at all. The
ability to reconstruct a camera motion path in 3D space with respect to
the real environment and to export it to any animation package will empower
animators to create highly specialized visual effects.
The Camera Parameter Reconstruction
Technique, CPRT, is proposed. From the input of a series of shape descriptions
with their corresponding models, 3D surfaces are recovered. The camera
trajectory is then reconstructed with respect to a chosen world coordinate
system. The CPRT also checks the incoming list of shape descriptions to
ensure that a continuous camera trajectory can be reconstructed. It provides
a report to alert the users if there is any missing data needed in any
particular frames for the reconstruction. Result from CPRT can be used
for augmenting real images.
Computation of Depth Map
for Re-Rendering
The objective of this project
is to compute depth maps based on given image sequences and to perform
re-rendering. A depth map is a 2D function that gives the depth (with respect
to the viewpoint) of an object point as a function of the image coordinates.
A surface can be obtained after an appropriate model is fitted to the computed
depth map. The surface extracted can thus be rendered for visualisation.
However, the same visualisation can be obtained directly from the depth
map without intermediate surface fitting. Recently a new approach to rendering
has emerged: image-based rendering. Image-based rendering systems generate
different views of an environment from a set of pre-acquired imagery. In
an image-based rendering system, the model consists of a set of images
of a scene and their corresponding depth maps. When the depth of every
point in an image is known, the image can be rendered from any nearby point
of view by projecting the pixels of the image to their proper 3D locations
and reprojecting them onto a new image plane. Thus, a new image of the
scene is created by warping the images according to their depth maps. A
principal attraction of image-based rendering is that it offers a method
of rendering arbitrarily complex scenes with a constant amount of computation
required per pixel.
Virtual Studio
Just as many TV news-rooms
are getting comfortable with computers, a new generation of technology
is arriving: virtual set. Virtual set technology allows the broadcasters
to use the same blue room as the site of several different shows with different
sets, and to switch from one to another virtually instantaneously. Virtual
sets also have the advantage of requiring less expensive employee time
for set-up, take-down and maintenance, and have the ability to be updated
quickly. One of the key problems of such technology is the tracking of
the camera's movement and orientation. Currently, this is usually done
mechanically. In this project, the tracking of the camera will be done
using a CCD camera. A grided wall will be used as the backdrop of the news-casting
room. By analysing the grid pattern of the wall, the technique is to recover
the camera's pose. Based on this information, the system will then generate
the required graphical background (set) that is synchronized with the camera's
motion.
Interactive Virtual Studio
The interactive virtual
studio (IVS) is an augmented reality system that is capable of creating
3D virtual objects dynamically as the camera moves through the real environment.
It enables virtual objects to blend in completely with the real environment.
The underlying algorithm is based on simulated motion recovery technique
(SMRT). The SMRT is used to extract 3D information from 2D image. With
this information, IVS can then render virtual objects into the real environment.
This project is a continuation of previous projects; focusing on adding
enhanced features and making the system more interactive.
3D Augmented Reality and
Profilometry (Seah Hock Soon and Anand Asundi)
With rapid advances in optical
metrology and computer technology, it is possible to obtain 3D information
of objects using non-contact methods with good accuracy. 3D visualization
provides a vivid and easily interpretable scene information as compared
2D imaging. This combination has application in many fields, such as augmented
reality and product reengineering. Profiles of 2.5D objects and 360 degrees
around a rotating object has been demonstrated and found to be quite successful.
However, for augmented reality, 3D profiling across a scene would be useful.
The scene could be tracked along a straight line or a circular path or
any random curve. Since the scene does not shift the lighting and imaging
has to be moving. Thus there is need to calibrate the camera location at
each stage. This is one area of investigation. Secondly in product reengineering
smaller object need to be profiled. What are the associated problems and
solutions to this need to be explored. |