# Micro Fourier Transform Profilometry ($\mu$FTP): 3D shape measurement at 10,000 frames per second

## TL;DR

The paper introduces Micro Fourier Transform Profilometry ($TP), a novel 3D imaging method capable of capturing transient events at 10,000 fps with high accuracy using only two patterns, enabling detailed analysis of fast-moving scenes.

## Contribution

$TP) is a new high-speed 3D measurement technique that significantly improves frame rate and reduces pattern requirements compared to existing methods.

## Key findings

- Achieves 10,000 fps 3D imaging of dynamic scenes.
- Reconstructs accurate, dense 3D point clouds with only two patterns.
- Successfully captures fast transient events like explosions and vibrations.

## Abstract

Recent advances in imaging sensors and digital light projection technology have facilitated a rapid progress in 3D optical sensing, enabling 3D surfaces of complex-shaped objects to be captured with improved resolution and accuracy. However, due to the large number of projection patterns required for phase recovery and disambiguation, the maximum fame rates of current 3D shape measurement techniques are still limited to the range of hundreds of frames per second (fps). Here, we demonstrate a new 3D dynamic imaging technique, Micro Fourier Transform Profilometry ($\mu$FTP), which can capture 3D surfaces of transient events at up to 10,000 fps based on our newly developed high-speed fringe projection system. Compared with existing techniques, $\mu$FTP has the prominent advantage of recovering an accurate, unambiguous, and dense 3D point cloud with only two projected patterns. Furthermore, the phase information is encoded within a single high-frequency fringe image, thereby allowing motion-artifact-free reconstruction of transient events with temporal resolution of 50 microseconds. To show $\mu$FTP's broad utility, we use it to reconstruct 3D videos of 4 transient scenes: vibrating cantilevers, rotating fan blades, bullet fired from a toy gun, and balloon's explosion triggered by a flying dart, which were previously difficult or even unable to be captured with conventional approaches.