单帧红外图像低频非均匀性噪声校正算法

Single Image Based Nonuniformity Correction Method in Infrared Camera

红外成像系统中,低频非均匀性噪声严重影响红外系统的成像效果,传统基于标定的方法无法对其进行有效的去除.为此,提出一种基于曲面拟合的低频非均匀性噪声校正算法,首先对含噪图像进行小波滤波,以抑制高频信息;然后利用场景和低频非均匀性噪声梯度的稀疏特性,建立关于非均匀性噪声曲面参数的l1正则化能量泛函,并利用ADMM方法求解最优的非均匀性噪声曲面参数;最后将原始图像减去估计的低频非均匀性噪声得到校正后的图像.使用中波红外热像仪拍摄得到红外图像,对仿真图像和实际图像进行校正,实验结果表明,该算法能明显降低图像的粗糙度和非均匀性值,且有效地去除低频非均匀性噪声.

In infrared imaging system,the low-frequency nonuniformity noise seriously affects the imaging performance of infrared system and traditional calibration-based methods can’t effectively remove it.A low-frequency nonuniformity correction method based on surface fitting model is proposed in this paper.Firstly,noisy image is filtered by wavelet to suppress high frequency information.Then,using the sparse characteristics of gradient information of scene and low-frequency nonuniformity noise,l1 regularized energy functional for surface parameters of nonuniformity noise is established.The ADMM method is used to solve the optimal nonuniformity noise surface parameters.Finally,the estimated low-frequency nonuniformity noise is subtracted from the original image to obtain the corrected image.In this paper,the scene with simulated image and real image are corrected respectively.Infrared images are obtained by the middle wave infrared thermal imager to correct simulated images and actual images.The experimental results show that the algorithm can significantly reduce the roughness and nonuniformity of images and effectively remove the low-frequency nonuniformity noise.