Abstract: With the development of marine fishery and underwater operation, under water monitoring and image processing play an important role in these areas. Due to the light attenuation of sea water and the scattering of suspended particles, the requiring of high resolution under water monitoring image is still a difficult work at present. This paper analyzes impact factors of underwater camera imaging quality and presents an improved dark channel prior algorithm for deep-sea camera imaging. The algorithm integrates the advantages of dark channel prior, image filtering and Retinex theory, implements defogging, noise reduction, color calibration as well as contrast enhancement. The experimental results show that the algorithm significantly improves the image sharpness and visual quality and can be widely used in deep-sea monitoring and image processing area.

Key words: under watering imaging, dark channel prior, Retinex theory, image quality evaluation