Color-and-polarization encoded annular LED array for real-time active polarization imaging

This paper proposes a real-time active polarization imaging technology based on a color-and-polarization-encoded annular LED array. By replacing conventional monochromatic light sources with red, green, and blue (RGB) linearly polarized annular LED arrays and employing a standard color camera, our method achieves polarization image acquisition without requiring specialized polarization cameras. Each wavelength-specific light source integrates 0°, 45°, and 90° linear polarizers, with nested annular LED arrays enabling composite illumination that eliminates polarization errors inherent in dichroic mirror-based beam combining. The system demonstrates enhanced polarization feature retrieval through channel crosstalk correction and white balance algorithms. Experimental results reveal three key advantages: (1) spatial resolution shows a twofold improvement compared to commercial color-filter-based division-of-focal-plane (DoFP) polarization cameras; (2) measurement accuracy exhibits a maximum error of 4.7% against ground-truth images obtained by rotating polarizer methods, particularly for objects with wavelength-independent Mueller matrix variations; (3) imaging speed reaches 39.34 FPS at native 2448×2048 resolution through GPU-accelerated polarization computation. This technology establishes a novel framework for efficient polarization imaging of dynamic targets, demonstrating significant potential for industrial inspection and biomedical applications.