Bayesian Deep Learning for Hyperspectral Image Classification With Low Uncertainty

Abstract

In recent years, deep learning models have been widely used for hyperspectral image (HSI) classification and most of existing deep learning-based methods merely focused on high classification accuracy. However, in real applications, classification with low uncertainty matters as much as accurate classification. Unfortunately, existing methods fail to consider uncertainty. To tackle this challenge, for the first time, Bayesian deep learning (BDL) is investigated to analyze the model uncertainty for HSI classification. Specifically, first, at the feature extraction stage, an HSI classification framework based on BDL, which contains two Bayesian Gabor layers and a global pooling layer (i.e., BDL-G <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ), is proposed. In BDL-G <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , parameters in Gabor layers are sampled from the Gaussian distribution. The proposed BDL-G <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> not only provides the uncertainty estimation, but also strengthens the structure characteristic (i.e., texture) of HSI. Second, to model the uncertainty at the final classification stage, BDL-G <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> is combined with a Bayesian fully-connected layer (i.e., BDL-G <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> -BFL), where the parameters’ distribution is adjusted adaptively. In the proposed BDL-G <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> -BFL, the uncertainty at feature extraction and classification stages are both captured, and a whole uncertainty estimation framework is established. Experimental results on the three public HSI datasets demonstrates the superiority in both accuracy and uncertainty. The proposed Bayesian deep learning-based methods pioneer a new direction and provide useful inspiration and experience for practical applications.