Object recognition requires robust and stable features that are unique in feature space.
Lie group analysis provides a constructive procedure to determine such features, called invariants, when they exist. A constructive algorithm is provided that fundamentally seeks to determine an integral submanifold which, in practice, is a good approximation to the orbit of the Lie group action. This idea is applied to the long-wave infrared problem and experimental results are obtained supporting the approach. Other application areas are cited. IEEE Transactions on Pattern Analysis and Machine Intelligence , Vol.