(a) Calibration of the PSG system: experimental four-quadrant images captured by the polarization camera under the red channel illumination for input SOPs as linear horizontal (H), vertical (V), antidiagonal (A), diagonal (D), circular left (R) and circular right (L). (b) The intensity profiles for inputs D and L. (c) Calculations of average values are performed in the central circle with diameter of 600 pixels.