A Practical Calibration Method for RGB Micro-Grid Polarimetric Cameras
This work addresses a practical calibration challenge for users of RGB polarimetric cameras in robotic vision applications, offering a simpler and more accessible solution compared to existing methods.
The authors tackled the problem of calibrating RGB micro-grid polarimetric cameras, which is crucial for accurate polarization measurements but previously required complex equipment and setups, by proposing a new method that allows easy calibration using a uniform, linearly polarized light source with limited acquisitions, and they will release the code publicly.
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.