Adaptive image enhancement method for document

This work proposes an adaptive image enhancement (AIE) method, is used to enhance handwritten document images. An AIE method is proposed to denoise handwritten documents in a wavelet domain, which differs from other methods in two aspects: Firstly, modified contrast limited adaptive histogram equalization (CLAHE) is used to equalize the contrast of an image by cutting the histogram at some threshold, and then equalization is used. Secondly, the image is improved by using directional transform enhancing for foreground and interfering strokes, respectively. In the experimental result, the proposed method not only removes the interfering strokes or visible watermarks in the background information, but also significantly increases the readability of handwritten document images.