Image Contrast Enhancing Method Based On Rough Set

According to the main problems such as excessive brightness change, noiseartifacts and brightness saturation in the image enhancement method are existed. Animage specification algorithm based on multi-peak Gaussian function is proposed andstudied in this paper. In this algorithm, local-means and local-variances can beestimated respectively with the method of derivative and multi-peak Gaussian functionof original histogram can be obtained which can be regarded as target histogram tomanage original histogram. A key feature of the algorithm is that the variance ofparameters of local-variances can control the image contrast selectively and locally. Forcolor image, the proposed algorithm can handle three sub-image (R,G,B) of color imagerespectively and then effectively combine R, G and B with the color recovery factor onthe habit of human vision.According to excessive brightness change, image contrast enhancement algorithmbased on Rough Set is introduced. In this algorithm, original histogram is fit byGaussian mixture model (GMM), and upper-approximation set R X andlower-approximation set R X of the objective function set X can be obtained byRough Set Theory. In order to effectively control the dynamic range of contrast andpreserve the brightness of original image, a roughness factor is proposed to control theshape of target histogram which can be used to handle original histogram. Experimentalresults and theoretical analysis demonstrate that the proposed algorithm can enhanceimage contrast and preserve the brightness of image which can enhance visual effect ofimage.