(AGENPARL) – lun 18 marzo 2024 *Source: *Tokyo Institute of Technology
*Immediate release: *March 19, 2024 (Tokyo, Japan)
*Headline: *An Innovative Mixed Light Field Technique for Immersive
Projection Mapping
*Body:* (Tokyo, March 19) A novel mixed light field technique that utilizes
a mix of ray-controlled ambient lighting with projection mapping (PM) to
obtain PM in bright surroundings has been developed by scientists at Tokyo
Institute of Technology. This innovative technology utilizes a novel
kaleidoscope array to achieve ray-controlled lighting and a binary search
algorithm for removing ambient lighting from PM targets. It provides an
immersive augmented reality experience with applications in various fields.
Projection mapping (PM) is a fascinating technology that provides an
immersive visual experience by projecting computer-generated images onto
physical surfaces, smoothly merging real and virtual worlds. It allows us
to experience augmented reality without the need for special glasses. As a
result, PM is in high demand in various fields including enhanced stage
productions, trying on clothing and make-up, and educational
demonstrations.
Despite its potential, current PM methods face challenges in bright
environments with ambient lighting. Ambient lighting drowns the entire
scene in light, reducing the contrast of PM targets. This is why
conventional PM solutions mainly function in dark environments. However,
even in dark environments, PM fails to provide a natural scene, as in a
dimly lit scene, only the PM target is well-lit while the rest of the
surroundings remain dark, causing it to appear overly bright. Additionally,
non-PM objects appear too dark, breaking the immersion.
To address these issues, a team of researchers from Japan, led by Associate
Professor Yoshihiro Watanabe from the Department of Information and
Communications Engineering at Tokyo Institute of Technology, has recently
developed an innovative new mixed light field approach for achieving PM in
brightly lit environments. “In this approach, instead of using normal
ambient light, we introduced a mixed light field in which a
ray-controllable light avoids the PM target while adequately lighting other
areas within the scene while the PM projector exclusively illuminates the
target,” explains Dr. Watanabe. Their findings were published in the
journal *IEEE Transactions on Visualization and Computer Graphics* and will
be presented at the 31st IEEE Conference on Virtual Reality and 3D User
Interfaces in Orlando, Florida USA, with the
presentation scheduled for March 19th at 1:30 PM local time(UTC-4).
At the center of this novel approach lies the ray-controllable lighting
unit. This unit reproduces a range of ambient lighting scenarios while also
avoiding illuminating the PM target. To achieve this, the researchers
developed a novel kaleidoscopic array comprising an array of mirrors
positioned behind a lens array, which, in turn, was placed in front of a
projector. This setup allowed the projector to produce a high-density light
field, crucial for ray-controllable lighting.
Furthermore, to avoid illuminating the PM target, the researchers deployed
a camera to capture images of the scene and identify the pixels from the
projector that illuminated the PM targets, subsequently turning them off.
To identify these pixels, they employed a simple binary-search-based
method, resulting in effective mixed light field.
This innovative approach allowed them to achieve high-contrast PM
presentations in brightly lit surroundings. Notably, it preserved the
natural appearance and shadows of ordinary non-PM objects, addressing a key
challenge in PM technology. Through several captivating augmented scenes,
the researchers showcased the seamless coexistence of PM targets and
ordinary objects, providing an immersive visual experience.
While the researchers identified some limitations, such as artefacts and
the low efficiency of binary search algorithms with large PM targets, they
have already identified potential solutions and are actively working to
expand this approach in the future.
“Our experiments prove the effectiveness of using this technique for
achieving natural PM presentations with accurate lighting for all objects.
Mixed light field has the potential to usher PM for various practical
day-to-day applications, such as attractions, for support in manufacturing
and trying on make-up
,” says Dr.
Watanabe, highlighting the applications of their technology.
Overall, this approach marks a significant step for PM technology, paving
the way for immersive augmented experiences in future.
Figure 1: https://tokyotech.box.com/s/16bkbxynwzm08s9rn3jt50j0wwnh470w
Figure 1. The entire configuration of the system (left) : from left to
right, the projection target, mirror-lens array, projector for projection
mapping, and projector for illumination. A close-up of the mirror-lens array.
This configuration reflects rays emerging from the lens array, leading to
an increased ray density (right).
Figure 2: https://tokyotech.box.com/s/u9j4p6w7ovnszmg3a7yuqd3kpmmrg72m
Figure 2 The high-contrast projection mapping achieved by the proposed
method, even under ambient light conditions (left). The conventional
projection mapping in a bright environment where the model on the left is
overexposed (top right). An unnatural situation where only the mapping
target is brightly lit in a dark environment (center right). The projection
mapping with ray-controllable ambient light, ensuring light does not cast
on the projection mapping target (bottom right).
*Contact: *Emiko Kawaguchi, Public Relations Department, Tokyo Institute
*About Tokyo Institute of Technology*
Tokyo Tech stands at the forefront of research and higher education as the
leading university for science and technology in Japan. Tokyo Tech
researchers excel in fields ranging from materials science to biology,
computer science, and physics. Founded in 1881, Tokyo Tech hosts over
10,000 undergraduate and graduate students per year, who develop into
scientific leaders and some of the most sought-after engineers in industry.
Embodying the Japanese philosophy of “monotsukuri,” meaning “technical
ingenuity and innovation,” the Tokyo Tech community strives to contribute
to society through high-impact research.
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