2. Common multi-class strategies for SVM
SVM, as one of themost effective statistical learning algorithms, uses
structural risk minimization (SRM) criterion rather than empirical risk
minimization (ERM) in other machine learning methods. Because
SVMis advantageous to mitigate such difficulties in hyperspectral classification
as small-size samples, high dimensionality, poor generalization
and uncertainty impacts, it has been employed to hyperspectral
RS image classification in recent years [3,4]. Although it is generally concluded
that SVMperforms better than other conventional classifiers and
it is suitable for high dimensional features (for example, the direct use
of all bands of hyperspectral image), the time consumption and computation
capacity are still challenging; therefore, feature extraction and dimensionality
reduction are still meaningful on many occasions.