Tech Briefs Magazine - June 2021 - 42

Imaging
The challenge, however, is that while the
photons in the X-ray beam carry two
pieces of information - the amplitude or
the brightness of the beam, and the phase
or how much the beam changes when it
passes through the sample - the detectors
only capture one. Because the detectors
can only detect amplitude and they
cannot detect the phase, all that information
is lost so it must be reconstructed.
It can be done but the process is slower
than scientists would like. Part of the challenge
is on the data acquisition end. In
order to reconstruct the phase data from
coherent diffraction imaging ex periments,
the current algorithms re quire scientists to
collect much more amplitude data from
their sample, which takes longer. But the
actual reconstruction from that data takes
some time as well. This is where PtychoNN
comes in. Using AI techniques, the re -
searchers demonstrated that computers
can be taught to predict and reconstruct
images from X-ray data and can do it 300
times faster than the traditional method.
More than that, though, PtychoNN is able
to speed up the process on both ends.
For more information, contact Mathew
Cherukara at mcherukara@anl.gov; 630252-4548.
3D
Holographic Head-Up Display Could Improve Road Safety
The LiDAR-based system could " see through " objects to warn of potential hazards without
distracting the driver.
University of Cambridge, United Kingdom
esearchers have developed a LiDARbased
augmented reality head-up
display for use in vehicles. Tests on a prototype
version of the technology suggest
that it could improve road safety by " seeing
through " objects to alert of potential
hazards without distracting the driver.
The technology uses LiDAR data to
create ultra-high-definition holographic
representations of road objects, which
are beamed directly to the driver's eyes
instead of 2D windscreen projections
used in most head-up displays.
The holographic images appear in the
R
driver's field of view according to their
actual position, creating an augmented
reality. This could be particularly useful
where objects such as road signs are hidden
by large trees or trucks, for example,
allowing the driver to see through
visual obstructions. Head-up displays
usually project information, such as
speed or fuel level, directly onto the
windscreen in front of the driver, who
must keep their eyes on the road. The
new system represents real objects as
panoramic 3D projections.
Using LiDAR, the team scanned a
busy street using a technique called terrestrial
laser scanning. Millions of pulses
were sent out from multiple positions
along the street. The LiDAR data was
then combined with point cloud data,
building up a 3D model. The scans were
stitched together, building a whole
scene that doesn't just capture trees but
cars, trucks, people, signs, and anything
else seen on a typical city street. Al -
though the data captured was from a stationary
platform, it is similar to the sensors
that will be in the next generation
of autonomous or semi-autono mous
vehicles.
42
Cov
An image based on LiDAR data (left), converted to a hologram (right).
When the 3D model of the street was
completed, the researchers then transformed
various objects on the street into
holographic projections. The LiDAR
data, in the form of point clouds, was
processed by separation algorithms to
identify and extract the target objects.
Another algorithm was used to convert
the target objects into computer-generwww.techbriefs.com
ToC
ated
diffraction patterns. These data
points were implemented into the optical
setup to project 3D holographic
objects into the driver's field of view.
The optical setup is capable of projecting
multiple layers of holograms with
the help of advanced algorithms. The
holographic projection can appear at
different sizes and is aligned with the
Tech Briefs, June 2021
http://www.techbriefs.com http://www.abpi.net/ntbpdfclicks/l.php?202106TBNAV
Tech Briefs Magazine - June 2021

Table of Contents for the Digital Edition of Tech Briefs Magazine - June 2021
