Researchers at Oxford
University have developed software
making it possible to fuse real and 3-D computer-generated visuals in real-time.
The software has great implications for AR (augmented reality) applications—it has the potential to greatly simplify AR development and allow the expansion
of AR to new application areas.
Called PTAM (Parallel Tracking and Mapping), the software
maps the images obtained using a video camera and turns the objects’ surfaces
into platforms for virtual objects without the need for pre-stored tags or prior
knowledge of the objects’ shapes and locations.
PTAM software in action (Source: University of Oxford).
PTAM potentially can help overcome limitations of current AR
implementations. In particular, current apps often rely on one of two methods
to identify objects.
In many AR applications created in controlled environments
such as computer labs or movie studios, the size, shape and location of all
objects are known in advance. A computer model of these objects is then used to
support the final AR animation or video.
A second approach is being used in many mobile phone-based
AR applications. Here, information such as the physical location and
orientation of the phone is gathered by the AR application. It then uses this
information in conjunction with an existing database to display the AR images
and virtual objects on the phone’s viewing screen.
An example of this latter technique is the WIKITUDE World Browser for the
iPhone 3GS. The application makes use of the iPhone’s digital compass, and
overlays information about landmarks from sources such as Wikipedia, Qype and
Wikitude.me.
In contrast to these two techniques, PTAM examines a video
view and attempts to identify in real-time items such as a book on a desk or a
building on a street. In particular, the software builds a detailed 3-D map of
the objects in a video frame. It can recognize objects from clusters of
features that form a “digital signature” of the items or location. As the map
is built, the camera’s viewpoint and angle are calculated so that 3-D AR images can
be projected into the video stream.
A demonstration of PTAM software running on an iPhone
acquiring images and building 3-D models can be seen in a YouTube video here.
Within the last month, Oxford
licensed the PTAM technology to AR company QderoPateo, which plans to
integrate the software into mobile phone applications to provide novel
advertising and other services.
AR for the masses
As venture capitalists fund AR startups and technologies such as
PTAM make their way into new applications that will run on mobile
phones,
an unlikely source is bringing AR to a potentially much wider audience.
The United States Postal Service has developed an
amazing AR application called the Virtual Box Simulator.
The simulator is aimed at people who use Priority Mail to ship items. With
Priority Mail and the USPS’s “If it fits, it ships” service, users pay a flat
rate to send an item based on the size of the box used.
The simulator helps users determine which size USPS box to
use. It requires a printer and a Webcam. To get started, you print an eagle
icon image and then launch the Virtual Box Simulator on a Web-connected
computer. You then place the eagle icon in front of a Webcam to trigger the AR
application.
The application generates a transparent box, and by placing
the object that needs to be shipped in the Webcam’s view, you can see if the
item fits in that sized box. You can interact with the AR image, changing its
transparency and orientation. If the item does not fit into the box you are
sampling, you simply select another size box. A demo of the USPS Virtual Box
Simulator can be seen here.
