中文摘要：

针对数字图像的频域增强，提出一种基于离散小波变换的Alpha-Rooting图像对比度增强方法．该方法利用小波的多分辨率性质，结合Alpha-Rooting图像对比度增强特点，对高频细节信号采用Alpha—Rooting算法增强，低频近似信号采用归一化增强算法．实验结果表明，该方法在EME与直方图两个尺度上，优于其他Alpha-Rooting增强算法（DCT、FFT）的对比度增强效果．

英文摘要：

The paper presents a new alpha-rooting image contrast enhancement method based on discrete wavelet transform （DWT）. Wavelet has the advantage of multi-resolution. Followed by the Wavelet composition, the paper proposes the image contrast enhancement algorithm to enhance the approximation information with normalization enhancement and details respectively with alpha-rooting enhancement. The experimental result shows the method is better and more effective than other methods such as DCT and FFT.