I. INTRODUCTION

II. THE THREE CATEGORIES OF HU METHODS

III. REVIEW OF THE STATE-OF-THE-ART HU METHODS

IV. HOW TO LABEL GROUND TRUTHS IN THE HU?

V. THE REAL HYPERSPECTRAL IMAGES

VI. THE SIMULATED HYPERSPECTRAL IMAGE

VII. EXPERIMENTS RESULTS OF 5 BENCHMARK HU METHODS ON THE 18 HYPERSPECTRAL IMAGES

VIII. CONCLUSION