Image restoration of luminous objects in dense fog

Images captured in dense fog are always severely degraded. For luminous objects, the luminance and contrast of the image are severely reduced due to the strong absorption of suspended particles. In this case, owing to the influence of forward scattered light and detector noise, the signal-to-noise ratio of the image is greatly reduced. Traditional image dehazing algorithms will enhance the noise while improving the image contrast. Here a dynamic equation-based filter is proposed, which can strongly suppress speckle and noise while improving target contrast. Based on this filter, we design an image restoration method for luminous targets in dense fog. The effectiveness of the proposed method is verified by experiments. The experimental results show that the proposed method has a good recovery effect on the luminous targets in dense fog with an optical thickness of 4.51. The proposed method has better performance than the traditional dehazing algorithms and conventional filtering method.