An FPGA-based image enhancement method for real-time water surface dense fog scenes

Abstract

The invention relates to a real-time water-surface fog scene image enhancement method based on an FPGA, and the method comprises the following steps: 1, carrying out the automatic white balance correction of an input image; 2, carrying out the color space transformation of the data after the white balance correction; 3, estimating the atmosphere light intensity A and the transmissivity t(x) through the dark primary color prior theory; 4, carrying out the defogging of the data of three channels RGB; 5, carrying out the brightness correction of the RGB channels after defogging; 6, carrying out the detail-maintaining contrast enhancement of the image after the automatic white balance correction; 7, carrying out the fusion of the image obtained at step 5 and an image obtained at step 6; 8, carrying out the color space inverse transformation of the image after fusion, and achieving the switching from an RGB color space to an original input color space. The method is used for the defogging of a water-surface fog scene, can remarkably enhance the details and contrast of the image, has a capability of finding and recognizing a target under the condition of water-surface fog, and enables avideo to be more suitable for human eyes.

Description

technical field [0001] The invention relates to an FPGA-based real-time water surface dense fog scene image enhancement method. Aiming at the problem of high concentration of water mist on the water surface and serious image degradation, the clear processing of the image is realized by integrating the method of solving the atmospheric scattering physical model and the contrast enhancement method , which belongs to the field of image processing and machine vision. Background technique [0002] With the development of computer vision system and its application in military, transportation and security monitoring and other fields, image enhancement has become an important research direction of computer vision. When imaging on the sea or water surface, due to the serious water fog, the image will be seriously degraded due to the effect of atmospheric scattering, which will make the image color off-white, reduce the contrast, and make it difficult to identify the object features, ...

AI Technical Summary

Problems solved by technology

[0004] The research on haze removal method is one of the hotspots in the field of machine vision at present, which has attracted the attention of many research institutions at home and abroad; the document "Single Image Haze Removal Using DarkChannel Prior" published in the top international conference CVPR in 2009 carried out the research on the method of haze removal. After research, good practical results have been achieved. However, since the sky area does not satisfy the dark channel prior, this method will cause distortion when processing foggy images with a large area of ​​sky. At the same time, the soft matting method for calculating the transmittance proposed in the article Although a relatively fine transmittance map can be obtained, the calculation is complicated and cannot meet the real-time requirements

[0005] Patent CN106023118A proposes an image defogging method and its implementation method on FPGA. Although the real-time defogging function of foggy scenes is realized, the contrast of the image and the edge of the target are not processed, and the image still has low contrast. The problem with the blurred edges of the target

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