Underwater image restoration method based on wavelength compensation

Abstract

The invention provides an underwater image restoration method based on wavelength compensation. The method comprises the following steps: performing nine-digit-based subdivision hierarchical search onan original image to estimate atmospheric light spots; and then calculating a transmission image by using a Haze-lines method in different Jerlov water types, compensating atmospheric light by usingdifferent attenuation coefficients, and calculating a distance image and a depth image to obtain a restored image. In order to further improve the contrast of the underwater image, a contrast-limitedadaptive histogram is used to enhance the restoration result. A final output image is determined according to a selection rule based on gray world hypothesis and information entropy. According to theinvention, the atmospheric light is obtained by using a nine-digit method, so that the influence of scenery and light spots on estimation of the atmospheric light is effectively avoided, and the atmospheric light is accurately estimated. The distance map and the depth map are estimated by using different water types, the underwater image degradation problem is effectively solved, and finally, thecontrast and the brightness of the image can be effectively enhanced by using the contrast-limited adaptive histogram for enhancement.

Description

Technical field [0001] The present invention relates to the field of underwater image processing, in particular, more particularly to a method of underlying underwater image restoration based on wavelength compensation. Background technique [0002] Due to the physical properties of underwater environment, underwater image processing is still challenging. In many cases, the acquisition of underwater images is degraded by absorption and scattering. In the underwater scene, the camera acquired by the camera mainly contains three parts, one is the direct component from the object reflected light; the second is that the target reflected light to the camera lens to encounter a small angle of the suspended particles in water, a small angle, a small angle, random scattering Scattering components; third, when light is irradiated into water, it encounters impurities in water, and scattering the rear scattering component received directly by the camera. Underwater image can be expressed as...

AI Technical Summary

Problems solved by technology

Additionally, suspended particles create unwanted noise

Degraded underwater images have certain limitations in information display and extraction of valuable information, such as marine environmental monitoring, marine ecological protection, archaeology, and marine resource exploration, etc.

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