The document image incorporating with image enhancement method can achieve a good perceptual quality

which is necessary for the document image information system. Contrast-limited Adaptive Histogram Equalization (CLAHE) is widely utilized to expand the global dynamic contrast range

and Lee filter is usually used to amplify the local details. A detail-amplifying CLAHE (DAHE) method is proposed by combining the above two methods. Firstly

a noise-resist policy is employed to differentiate the detail and the noise. Secondly

a flexibility amplifying mechanism is proposed to make the amplified image suitable for the human vision system. The proposed method can not only balance the global gray-level dynamic range

but also enhance the local details. The experimental results demonstrate that the proposed method can both enhance the document image

which is suitable for the document image information system

and satisfy the requirements of the national industry standard.