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

Abstract

The invention relates to a real-time water surface thick fog scene image enhancement method based on FPGA, which includes the following steps: first, perform automatic white balance correction on the input image; second, perform color space transformation on the data after white balance correction; third, Using the dark primary color prior theory, the atmospheric light intensity A and transmittance t(x) are estimated; fourth, the three RGB channel data are dehazed respectively; fifth, the RGB channel after dehazing is corrected for brightness; third Sixth, perform detail-preserving contrast enhancement on the image after automatic white balance correction; Seventh, perform image fusion on the images obtained in steps five and six; Eighth, perform inverse color space transformation on the fused image, as follows: The RGB color space is changed to the color space of the original input. The invention has a defogging effect for scenes of dense fog on the water surface, can significantly enhance image details and contrast, enhances the ability to find and identify targets in the case of dense fog on the water surface, and makes the video more suitable for human eyes to watch.

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, ...

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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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