Finding Significant Features for Few-Shot Learning using Dimensionality Reduction

TL;DR

This paper proposes using dimensionality reduction to identify task-significant features in few-shot learning, improving the discriminative power of similarity functions and outperforming baseline methods on miniImageNet.

Contribution

It introduces a novel approach that applies dimension reduction techniques to enhance feature selection in metric-based few-shot learning.

Findings

Achieved around 2% accuracy improvement on miniImageNet

Selected features with better intra- and inter-class separation

Enhanced the discriminative ability of similarity functions

Abstract

Few-shot learning is a relatively new technique that specializes in problems where we have little amounts of data. The goal of these methods is to classify categories that have not been seen before with just a handful of samples. Recent approaches, such as metric learning, adopt the meta-learning strategy in which we have episodic tasks conformed by support (training) data and query (test) data. Metric learning methods have demonstrated that simple models can achieve good performance by learning a similarity function to compare the support and the query data. However, the feature space learned by a given metric learning approach may not exploit the information given by a specific few-shot task. In this work, we explore the use of dimension reduction techniques as a way to find task-significant features helping to make better predictions. We measure the performance of the reduced features by assigning a score based on the intra-class and inter-class distance, and selecting a feature reduction method in which instances of different classes are far away and instances of the same class are close. This module helps to improve the accuracy performance by allowing the similarity function, given by the metric learning method, to have more discriminative features for the classification. Our method outperforms the metric learning baselines in the miniImageNet dataset by around 2% in accuracy performance.