Imaging in turbid water based on a Hadamard single-pixel imaging system.

Underwater imaging is a challenging task because of the large amounts of noise and the scattering nature of water. Conventional optical methods cannot realize clear imaging in underwater conditions owing to the limitations of low sensitivity, geometrical aberrations, and the narrow spectrum of photoelectric detectors. By contrast, single-pixel imaging (SPI) is a promising tool for imaging in poor-visibility environments. Nevertheless, this challenge is faced even when using traditional SPI methods in highly turbid underwater environments. In this work, we propose a Hadamard single-pixel imaging (HSI) system that outperforms other imaging modes in turbid water imaging. The effects of laser power, projection rate, and water turbidity on the final image quality are systematically investigated. Results reveal that compared with the state-of-the-art SPI techniques, the proposed HSI system is more promising for underwater imaging because of its high resolution and anti-scattering capabilities.