Abstract: Because of noise and low contrast in the infrared image, an efficient enhancement method for infrared image is proposed. Evaluating function is constructed by combining information entropy, signal-noise-ratio with standard variance in order to evaluate the enhanced image quality. According to property of infrared image, an efficient nonlinear transformation function is designed by arc-tangent transformation in stationary wavelet domain so as to enhance the contrast of an infrared image. The optimal nonlinear transformation parameter is obtained by combining differential evolution algorithm with the constructed evaluating function. Experimental results show that the proposed algorithm can efficiently enhance the contrast of the infrared image while having a good robustness to noise in the infrared image. The overall performance of the proposed algorithm is better than that of two traditional similar methods.

Key words: infrared image, enhancement, stationary wavelet transformation, differential evolution algorithm, arc-tangent transformation

摘要： 针对红外图像噪声大、对比度低等特点，提出一种平稳小波域的红外图像增强方法。综合运用信息熵、信噪比和图像的标准差构造增强后图像的评价函数。结合红外图像的特点，利用反正切变换设计一种简单有效的非线性变换函数用于在平稳小波域内增强红外图像的对比度。该算法用差分演化算法结合构造的评价函数，寻找最优的非线性变换参数。实验结果表明，所提出的算法在有效增强红外图像对比度的同时又对噪声有较强的鲁棒性。所提出的算法综合性能优于两种传统的同类方法。

关键词: 红外图像, 增强, 平稳小波变换, 差分演化, 反正切变换