Publication Type
Journal Article
Version
acceptedVersion
Publication Date
6-2022
Abstract
Few-shot classification studies the problem of quickly adapting a deep learner to understanding novel classes based on few support images. In this context, recent research efforts have been aimed at designing more and more complex classifiers that measure similarities between query and support images but left the importance of feature embeddings seldom explored. We show that the reliance on sophisticated classifiers is not necessary, and a simple classifier applied directly to improved feature embeddings can instead outperform most of the leading methods in the literature. To this end, we present a new method, named DCAP, for few-shot classification, in which we investigate how one can improve the quality of embeddings by leveraging Dense Classification and Attentive Pooling (DCAP). Specifically, we propose to train a learner on base classes with abundant samples to solve dense classification problem first and then meta-train the learner on plenty of randomly sampled few-shot tasks to adapt it to few-shot scenario or the test time scenario. During meta-training, we suggest to pool feature maps by applying attentive pooling instead of the widely used global average pooling to prepare embeddings for few-shot classification. Attentive pooling learns to reweight local descriptors, explaining what the learner is looking for as evidence for decision making. Experiments on two benchmark datasets show the proposed method to be superior in multiple few-shot settings while being simpler and more explainable.
Keywords
few-shot learning, image classification, visual recognition, meta-learning, attention networks
Discipline
Databases and Information Systems | Graphics and Human Computer Interfaces
Research Areas
Data Science and Engineering
Publication
ACM Transactions on Multimedia Computing, Communications and Applications
Volume
18
Issue
2s
First Page
1
Last Page
23
ISSN
1551-6857
Identifier
10.1145/3511917
Publisher
Association for Computing Machinery (ACM)
Citation
HE, Jun; HONG, Richang; LIU, Xueliang; XU, Mingliang; and SUN, Qianru.
Revisiting local descriptor for improved few-shot classification. (2022). ACM Transactions on Multimedia Computing, Communications and Applications. 18, (2s), 1-23.
Available at: https://ink.library.smu.edu.sg/sis_research/7558
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Additional URL
https://doi.org/10.1145/3511917
Included in
Databases and Information Systems Commons, Graphics and Human Computer Interfaces Commons