Hidden Markov model approaches to hyperspectral image classification

In this paper, we present a hidden Markov model (HMM) approach to hyperspectral image classification. HMMs have been widely used in speech recognition to model a doubly stochastic process with a hidden state process that can be only observed through a sequence of observations. Since the temporal variability of a speech signal is similar to the spectral variability of a remotely sensed image pixel vector, the same idea can be applied to hyperspectral image classification. It makes use of a hidden Markov process to characterize the spectral correlation and band-to-band variability where the model parameters are determined by the spectra of the pixel vectors that form the observation sequences. Experiments demonstrate that the HMM can better describe the unobserved spectral properties so as to improve classification performance.