关键词: 分数阶微分, 图像增强, 图像特征分块, 图像熵, 峰值信噪比

Abstract: To improve the effect of image enhancement and highlight the image subject, a new fractional-order differential image enhancement algorithm is proposed based on image characteristics division. By constructing a fractional-order differential mask operator, the different fractional orders are determined according to the results of image features segmentation, and a matrix with the orders is generated. The matrix is substituted into the mask operators to calculate with the original image. During the experiments, the original image and the image added Gaussian noise are processed respectively. In addition, the effect of enhanced images is compared in the case of different parameters. Experimental results show that the algorithm enhances the texture of the main part of the image significantly and restrains the increase of image noise in background and smooth area to a certain extent. This algorithm has a better performance on increasing image texture when the average image gradient is slightly lower than that of the traditional fractional-order differential image enhancement algorithm.

Key words: fractional-order differential, image enhancement, image characteristics division, image entropy, Peak Signal to Noise Ratio（PSNR）