Improving performance of LMS non-uniformity correction by sigma filter

Spatial smoothing filters are usually used in LMS-based non-uniformity correction methods to get an estimation of true scene. Edge-smearing of these filters is the main reason for 'ghosting' artifacts. A method based on sigma filter is proposed, which can improve accuracy of non-uniformity and mitigate 'ghosting' artifacts. Sigma filter is also used to detect abnormal pixels and adaptively adjust learning rate. Tests with simulated data and real infrared sequences have shown that the proposed method outperforms other representative LMS-based methods.