  Aiming at the problems of color distortion, blur and excessive noise of
underwater image, an underwater image enhancement algorithm based on
structure-texture reconstruction is proposed. Firstly, the color equalization
of the degraded image is realized by the automatic color enhancement algorithm;
Secondly, the relative total variation is introduced to decompose the image
into the structure layer and texture layer; Then, the best background light
point is selected based on brightness, gradient discrimination, and hue
judgment, the transmittance of the backscatter component is obtained by the red
dark channel prior, which is substituted into the imaging model to remove the
fogging phenomenon in the structure layer. Enhancement of effective details in
the texture layer by multi scale detail enhancement algorithm and binary mask;
Finally, the structure layer and texture layer are reconstructed to get the
final image. The experimental results show that the algorithm can effectively
balance the hue, saturation, and clarity of underwater image, and has good
performance in different underwater environments.
