Power-compensated white laser based on light source angle for underwater imaging applications

The attenuation characteristics of light in water, light source configuration parameters, etc. affect the absorption and scattering of light, which in turn affects the image quality. To study the influence of the light source angle of the white laser on the quality of underwater imaging, a power-compensated combined beam white laser is used as the underwater illumination light source according to the theory of underwater optical propagation. A white laser underwater imaging system for light source angles is proposed based on the Jaffe–McGlamery physical model of classical underwater imaging. The variation of the image signal-to-noise ratio with the light source angle is derived and the simulation curve is plotted. Relevant underwater imaging experiments were conducted, and the images were optimised using the multi-scale Retinex and lap fusion algorithms. By analysing the image quality evaluation parameter peak signal-to-noise ratio of the actual image, the signal-to-noise ratio of the image is greatest when the angle between the power-compensated white light source and the camera is 90°, which is consistent with the conclusion of the model simulation and verifies the correctness of the theoretical model. The results provide a partial database and experimental basis for the construction of the structural form of the white laser underwater illumination imaging system and provide a new option and solution for the optimisation of the light source type for underwater imaging.