A Comparative Analysis of Swarm Intelligence and Evolutionary Algorithms for Feature Selection in SVM-Based Hyperspectral Image Classification

Feature selection (FS) is vital in hyperspectral image (HSI) classification, it is an NP-hard problem, and Swarm Intelligence and Evolutionary Algorithms (SIEAs) have been proved effective in solving it. However, the high dimensionality of HSIs still leads to the inefficient operation of SIEAs. In addition, many SIEAs exist, but few studies have conducted a comparative analysis of them for HSI FS. Thus, our study has two goals: (1) to propose a new filter-wrapper (F-W) framework that can improve the SIEAs' performance; and (2) to apply ten SIEAs under the F-W framework (F-W-SIEAs) to optimize the support vector machine (SVM) and compare their performance concerning five aspects, namely the accuracy, the number of selected bands, the convergence rate, and the relative runtime. Based on three HSIs (i.e., Indian Pines, Salinas, and Kennedy Space Center (KSC)), we demonstrate how the proposed framework helps improve these SIEAs' performances. The five aspects of the ten algorithms are different, but some have similar optimization capacities. On average, the F-W-Genetic Algorithm (F-W-GA) and F-W-Grey Wolf Optimizer (F-W-GWO) have the strongest optimization abilities, while the F-W-GWO requires the least runtime among the ten. The F-W-Marine Predators Algorithm (F-W-MPA) is second only to the two and slightly better than F-W-Differential Evolution (F-W-DE). The F-W-Ant Lion Optimizer (F-W-ALO), F-W-I-Ching Divination Evolutionary Algorithm (F-W-IDEA), and F-W-Whale Optimization Algorithm (F-W-WOA) have the middle optimization abilities, and F-W-IDEA takes the most runtime. Moreover, the F-W-SIEAs outperform other commonly used FS techniques in accuracy overall, especially in complex scenes.