Time-of-Flight Imaging in Fog Using Polarization Phasor Imaging

Area of Science:

• Optics
• Computer Vision
• Remote Sensing

Background:

• Atmospheric aerosols scatter light, degrading image contrast and distorting depth measurements in time-of-flight (ToF) imaging.
• This limitation restricts the use of ToF imaging in outdoor environments, including autonomous driving systems.

Purpose of the Study:

• To develop a novel method for recovering high-quality amplitude and depth information from ToF images captured in foggy conditions.
• To enhance the applicability of ToF imaging for outdoor sensing technologies.

Main Methods:

• Introduced optical polarimetric defogging into ToF phasor imaging.
• Proposed a degree of polarization phasor to estimate the scattering component.
• Established a polarization phasor imaging model to separate target and scattering components.

Main Results:

• Successfully recovered amplitude and depth information from ToF signals.
• Demonstrated significant improvements in image quality in foggy scenes through experiments with artificial fog.
• Confirmed the method's robustness across varying fog densities.

Conclusions:

• The proposed polarization phasor imaging method effectively recovers image amplitude and depth in foggy conditions.
• This advancement broadens the potential applications of ToF imaging in challenging weather scenarios.