The company Pix4D collects a database of landscape using a flying drone, which tags each photo with a location and time. This information helps build a 3D model using cloud computing resources. The concept allows users to watch the 3D models change through time. |
Wouldn’t
it be cool if you could upload a bunch of photos of your favorite
building and your computer could spit out a stunning 3D model?
Researchers in EPFL’s Computer Vision Laboratory thought so. They
developed a computer program that generates a 3D image from up to
thousands of 2D shots, with all the processing done in the cloud. Since
April, the EPFL start-up Pix4D has been offering the modeling service
with an intriguing plus: a fourth dimension—time. Now, individuals and
small businesses looking for fast, cheap, large-scale 3D models can get
them without investing in heavy processing.
“All
the information we need to make a 3D model is contained in the photos
and the differences we find among them,” explains Pascal Fua, head of
the Computer Vision Laboratory. “Along with the image, our program takes
additional information such as the time the photo was taken and even
corrects the GPS location for more precise localization.”
With
Pix4D, users upload a series of photos of an object and within 30
minutes they have a 3D image. The software defines “points of interest”
from among the photos, or common points of high contrast pixels. Next,
the program pastes the images together seamlessly by matching up the
points of interest. Much in the same way our two eyes work together to
calculate depth, the software computes the distance and angle between
two or more photos and lays the image over the model appropriately,
creating a highly accurate 3D model that avoids the time intensive,
“point by point” wireframe method.
“For
one project, we’ve processed over 50,000 photos, taken mostly by
students, and created a high-resolution 3D model of the old city of
Lausanne,” explains Pix4D founder and EPFL post-doc Christoph Strecha.
With
Pix4D’s 3D models, you can navigate in all directions as well as change
the date on a timeline to see what a place looked like at different
times of the year. The company is collaborating with several drone
makers among which is another EPFL startup called senseFly to market
their software as a package with senseFly’s micro aerial vehicles, or
autonomous drones.
Adding the fourth dimension
Pix4D’s
time element is especially intriguing for senseFly’s customers. Instead
of waiting for Google to update its satellite data or for an expensive
plane to fly by and take high-resolution photos, farmers, for example,
can now send relatively inexpensive flying drones into the air to take
pictures as often as they like, allowing them to survey the evolution of
their crops over large distances and long periods of time. And since
the calculations are done on a cloud server, the client doesn’t need a
powerful computer of his or her own.
