Retinex underwater image enhancement method based on gray value mapping

Abstract

The invention provides a Retinex underwater image enhancement method based on gray value mapping. The Retinex underwater image enhancement method comprises five processes of color correction, filtering and denoising, establishment of a gray mapping function, searching of optimal parameters and contrast enhancement. The method comprises the following steps: firstly, carrying out color correction ona collected underwater degraded image by adopting a multi-scale Retinex algorithm with a color recovery factor to obtain a first output image; secondly, performing contrast enhancement on the first output image by adopting anisotropic diffusion filtering to obtain a second output image; establishing a gray value mapping function; then, according to the information entropy and the global brightness mean value of the image, combining a simulated annealing algorithm to quickly search for an optimal parameter value, and perfecting a gray value mapping function; and finally, carrying out gray value mapping on the second output image to obtain a final enhanced image. Under the condition of not needing any prior information, underwater image color correction and contrast enhancement are effectively achieved, the image visual effect is improved, and the method can be applied to underwater image preprocessing.

Description

technical field [0001] The invention relates to the technical field of underwater image enhancement, in particular to a Retinex underwater image enhancement method based on gray value mapping. Background technique [0002] With the increasing shortage of land resources, the development of marine resources has become the focus of attention of all countries. Underwater detection technology is of great significance to the exploration of marine resources, environmental monitoring and marine military affairs. As an important carrier for obtaining ocean information, underwater images are closely related to underwater imaging systems. Underwater degraded images directly impact applications. The images collected underwater are different from those taken on land. The imaging environment and lighting conditions lead to color cast, low contrast and blurred details of underwater images. [0003] With the rapid development and maturity of image processing and computer vision technolog...

AI Technical Summary

Problems solved by technology

To a certain extent, the underwater image enhancement method can effectively improve the visual effect of the image, but there are noise amplification, artifacts and color distortion, which cannot completely solve the problem of underwater image degradation.

The underwater image restoration method relies on the underwater degradation model, which needs to obtain prior knowledge, and the algorithm has certain limitations

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