一种基于小波变换的非线性红外图像增强算法

A Nonlinear Algorithm of Infrared Image Enhancement Based on Wavelet Transform

针对红外图像对比度低,噪声干扰大,用传统增强算法增强时,增大噪音的问题,提出了一种基于小波变换的非线性红外图像增强算法。该算法先对原始图像进行小波变换获得低频和高频系数,接着根据低频系数的特点设计了非线性函数对低频系数进行增强,并对高频系数进行小波去噪,最后通过小波重构得到增强的图像。仿真实验表明,该方法不仅解决了红外图像对比度低的问题,并且降低了噪声,突出了图像细节,该方法无论是增强效果还是抗噪效果都明显优于传统的图像增强方法。

For infrared image with the characteristics of low contrast and low signal-to-noise, traditional methods for image enhancement not only cannot capture the geometric information but also tend to amplify noise. A Nonlinear Algorithm of Infrared Image enhancement based on Wavelet Transform is presented. Firstly, the wavelet transform is adopted to decompose the input infrared image. Secondly, wavelet threshold is used for image de-noising and low frequency coefficients are enhanced by the designed nonlinear function. Finally, the inverse wavelet transform is applied to synthesis image which can obtain the enhanced image. A group of experimental results demonstrate that the presented algorithm not only solves the problem of the low contrast in infrared image, but also reduces the noise and highlight the image detail. The proposed algorithm outperforms the traditional image enhancement methods.