INRS's C-BLIP method records 3D shape of moving objects at up to 150,000 frames per second

A team led by Jinyang Liang at the Institut National de la Recherche Scientifique (INRS) in Quebec announced C-BLIP, chromatically band-limited illumination profilometry, on Nov. 12. According to tech.yahoo.com, the method records the 3D shape of a moving object at up to 150,000 frames per second. tech.yahoo.comtech.yahoo.comtech.yahoo.comOpen source ↗ The authors say this sets a new world record in 3D profilometry.

Why fast events are hard to measure

Profilometry measures an object's surface shape. Most 3D profilometry projects light patterns onto an object and reconstructs its shape from how the patterns distort. Researchers describing related systems note that this approach is limited by the speed of the projector and camera and by the number of patterns each 3D frame requires.

Many fast events, such as collisions, cannot be repeated on demand, so each must be captured in a single take. The INRS team adds that existing ultrafast 3D systems are often held back by slow acquisition, computationally heavy image reconstruction or the high cost of specialized equipment.

To address this, the team combined a cost-effective optical design with eye-safe LED illumination and a lightweight reconstruction method. The researchers say this makes ultrafast 3D imaging more practical for a wide range of research environments, not only specialized labs. tech.yahoo.comtech.yahoo.comtech.yahoo.comOpen source ↗

Experiments and record context

In experiments, C-BLIP recorded a projectile colliding with a turbofan blade, the aerodynamics of a falling maple samara and the vibrations of a loudspeaker membrane. The team also detected ultrasonic vibrations on an object's surface and extracted acoustic information from them, recovering a spoken message.

The record claim applies only to 3D profilometry. Earlier ultrahigh-speed systems in this field reported about 100,000 frames per second, including a previous band-limited illumination system presented by Liang. Methods that capture light in flight run at billions or trillions of frames per second, but they do not measure surface shape in the same way.

The researchers see uses in mechanics and aerodynamics, microfluidics, high-rate material testing and additive manufacturing. tech.yahoo.comtech.yahoo.comtech.yahoo.comOpen source ↗ The team is now optimizing the system by adding GPU-accelerated processing, which could eventually allow real-time visualization of such events.