Non-uniform illumination image enhancement algorithm based on parametric fuzzy transformation

Aiming at the problem of low contrast and low definition in non-uniform illumination images, an algorithm for enhancing image contrast using parametric fuzzy transform in luminance domain was proposed. The algorithm converts the color image from RGB space to HSV color space and LUV color space firstly, and secondly applies the fuzzy transform in the luminance domain of LUV to smooth the brightness distribution of the original image. In order to enhance the contrast of the image and improve the detail of the dark region, we introduce a parameter related to the HSV spatial value layer in the membership function. Then the proposed algorithm utilizes the pixel weighting strategy in the HSV spatial value layer to preserve a large amount of texture information. Finally, both the images are combined to form the enhanced image in HSV space and transformed to RGB space, which obtained a high quality image with naturalness preservation. The experimental results show that the overall performance of the proposed method is better than other algorithms. While effectively enhancing the contrast of non-uniform illumination images, the subjective and objective quality of the image is also greatly improved.