Fuzzy Transform for Contrast Enhancement of Nonuniform Illumination Images

Contrast enhancement of nonuniform illumination image is a challenging area of image processing. Retinex-based algorithms have been widely adopted to enhance nonuniform illumination images for decades. But the idea of enhancing reflectance layer by removing the illumination is quite unreasonable and often results in poor ambiance. In this letter, we propose an algorithm to regularize the image illumination by utilizing the fuzzy transform in the luminance domain. In order to preserve the color and quality of the enhanced image, proposed algorithm is performed on value component of HSV space. The experimental results conducted on benchmark test images with qualitative and quantitative measures demonstrate the significance of the proposed algorithm. In addition, compared to the existing state-of-art methods, the proposed algorithm produces naturalness-preserved high-quality enhanced image with low computational cost.