Metric-Based Few-Shot Learning for Pollen Grain Image Classification

Pollen is an important substance produced by seed plants. They contain the male gametes which are necessary for fertilization and the reproduction of flowering plants. The scientific study of pollen, palynology, plays a crucial role in a number of disciplines, such as allergology, ecology, forensics, as well as food-production. Current trends in climate research indicate an increasing importance of palynology, partly due to a projected rise in allergies. Pollen detection and classification in microscopic images via deep neural networks has been studied and researched, however, pollen data is often sparse or imbalanced, especially when compared to the number of plant species, which is estimated to be between 330,000 and 450,000, of which only a small percentage is investigated. In this work, we present a solution that does not require a large number of data samples by employing Few-Shot Learning. Our work shows, that by utilizing Prototypical Networks, an average classification accura cy of 90% can be achieved on state-of-the-art pollen data sets. The results can be further improved by fine-tuning the net, achieving up to 98% accuracy on novel classes. To our best knowledge, this is the first attempt at applying Few-Shot Learning in the field of pollen analysis.