关键词: 非线性锐化算法, 细节增强, 噪声限制

Abstract: Image sharpening is a method which makes the digital image much more clearly by compensating outlines and sharpening edges of image.When normal sharpening algorithm performs high frequency enhancement，the obvious noises are also enhanced.Aiming at the detects，a non-linear image sharpening approach is proposed based on noise estimation which can be controlled.Because the details and noises of the image are difficult to distinguish，the algorithm can control the parameter to divide the noise from the edge.Experiment results demonstrate that this algorithm can not only sharpen the edge，but also suppress the noise，this algorithm enhances the image detail，the values of PSNR and DV/BV are higher，moreover the image enhanced has good visual effect.

Key words: non-linear sharpening algorithm, detail enhancement, noise estimation