“Doppler Time-of-Flight Rendering” by Kim, Jarosz, Gkioulekas and Pediredla
Conference:
Type(s):
Title:
- Doppler Time-of-Flight Rendering
Session/Category Title: Computer Vision
Presenter(s)/Author(s):
Abstract:
We introduce Doppler time-of-flight (D-ToF) rendering, an extension of ToF rendering for dynamic scenes, with applications in simulating D-ToF cameras. D-ToF cameras use high-frequency modulation for illumination and exposure, and measure the Doppler frequency shift to compute the velocity of dynamic objects. The time-varying scene geometry and high-frequency modulation functions used in such cameras make it challenging to accurately and efficiently simulate their measurements with existing ToF rendering algorithms. We overcome these challenges in a twofold manner: To achieve accuracy, we derive path integral expressions for D-ToF measurements under global illumination and compute these integrals with unbiased Monte Carlo estimates. To achieve efficiency, we develop a tailored time-path sampling technique that combines antithetic time sampling with correlated path sampling. We demonstrate experimentally that our sampling technique achieves ×100 acceleration compared to naive time-path sampling across different D-ToF camera models. We provide an open-source simulator that serves as a digital twin for D-ToF imaging systems, allowing imaging researchers, for the first time, to investigate the impact of various modulation functions, material properties, and global illumination on D-ToF imaging performance.
