A Practical Calibration Method for RGB Micro-Grid Polarimetric Cameras

TL;DR

This paper introduces a practical calibration method for RGB micro-grid polarimetric cameras that simplifies the process, requiring only a uniform polarized light source and minimal setup, making calibration accessible and efficient.

Contribution

The paper presents a new calibration technique specifically designed for RGB polarimetric cameras that avoids complex equipment and extensive experiments, enabling easy and quick calibration.

Findings

Calibration can be performed with a simple polarized light source.

Method does not require prior knowledge of the light source's polarization.

Calibration process is efficient and user-friendly.

Abstract

Polarimetric imaging has been applied in a growing number of applications in robotic vision (ex. underwater navigation, glare removal, de-hazing, object classification, and depth estimation). One can find on the market RGB Polarization cameras that can capture both color and polarimetric state of the light in a single snapshot. Due to the sensor's characteristic dispersion, and the use of lenses, it is crucial to calibrate these types of cameras so as to obtain correct polarization measurements. The calibration methods that have been developed so far are either not adapted to this type of cameras, or they require complex equipment and time consuming experiments in strict setups. In this paper, we propose a new method to overcome the need for complex optical systems to efficiently calibrate these cameras. We show that the proposed calibration method has several advantages such as that any user can easily calibrate the camera using a uniform, linearly polarized light source without any a priori knowledge of its polarization state, and with a limited number of acquisitions. We will make our calibration code publicly available.