Underwater target detection image enhancement method adopting self-adaptive multi-scale dark channel prior

Abstract

The invention discloses an underwater target detection image enhancement method adopting self-adaptive multi-scale dark channel prior. The method comprises steps as follows: acquiring an original color image of an underwater target; calculating a light vector of the original image; calculating a dark channel image of the original image; calculating transmission graphs corresponding to different-scale windows of the dark channel image; calculating steerable filter output images corresponding to the transmission graphs in different-scale windows of the original color image with a steerable filter method; primarily selecting several most appropriate windows in the minimum filter scale according to the condition that the error between each steerable filter output image and the corresponding transmission graph is minimum; performing weighted average on the screened-out steerable filter output images; calculating a restored and enhanced image of the original image according to the dark channel prior theory; performing quantitative evaluation on the restored image J in the mean value, the variance, the contrast ratio, the information entropy and other aspects. With the adoption of a steerable filter function applied in the method, texture and smoothness balancing processing on the image can be realized, so that the processed image has improved visual quality and rich texture information.

Description

technical field [0001] The invention belongs to the field of image information processing, and in particular relates to an adaptive multi-scale dark channel prior image enhancement method for underwater target detection. Background technique [0002] Underwater target detection images have special situations such as non-uniform brightness, low signal-to-noise ratio, and low contrast. Commonly used underwater target detection image enhancement algorithms are mainly divided into two categories: modifying the illumination of underwater images and suppressing image contrast to preserve image edges. , but it will inevitably reduce the visual quality of the detection image. Based on the light scattering physical model, the prior condition is used for image reverse restoration, the most classic Dr. He Kaiming's dark channel prior dehazing method. The dark channel prior method selects a scale parameter to calculate the minimum value of each pixel component in the corresponding scal...

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Problems solved by technology

Due to the influence of the optical characteristics of water and various particles, plankton and water flow in water, it is difficult to directly translate and transfer the research results of dark channel prior theory to enhance underwater detection images: 1. Because only one Scale parameters, for detection images with large bright areas, the processing result error is large; 2. The image enhancement process is an open-loop system, which does not have the possibility of adaptively adjusting the scale parameters according to the enhancement effect evaluation index parameters

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