冷像是影响制冷型红外探测器成像质量的重要因素。虽然可以通过非均匀校正技术进行去除, 但当校正后的工作条件发生改变时, 冷像的影响又会显现出来。根据冷像产生的机理以及频率特点, 提出了一种基于时空估计的冷像校正算法。首先, 通过使用小波分解与重构对原始图像进行冷像噪声空间域估计; 然后, 利用自适应时域低通滤波获得冷像噪声的时间域估计; 最后, 利用原始图像与获得的冷像估计噪声做差完成校正过程。使用仿真和实际的红外图像序列进行实验, 结果表明所提算法能够有效地去除冷像噪声。

Narcissus effect was an important factor that influence the imaging quality of the cooled infrared detector. Although it can be removed by non-uniform correction techniques, narcissus effect will reappear once the operating conditions have changed. Through analyzing the manifestation of narcissus effect, a correction algorithm based on adaptive spatial-temporal filtering was proposed. First, spatial domain estimation of Narcissus effect was captured by wavelet transform. Then, time domain estimation of Narcissus effect was gained by adaptive time domain low-pass filtering. Finally, the correction was applied by subtracting the estimated spatial-temporal noise from the original image. Experimental results on simulated and actual infrared image sequences have verified the effectiveness of the proposed algorithm.