Pattern recognition (psychology)

Pure mathematics

Mathematics

Contextual image classification

Outlier

Categorization

Image (mathematics)

Parametric statistics

Statistics

Machine learning

Artificial intelligence

Verb

Computer science

Subcategory

Subcategorization

Classifier (UML)

IEEE Transactions on Neural Networks and Learning Systems

Studies present that dividing categories into subcategories contributes to better image classification. Existing image subcategorization works relying on expert knowledge and labeled images are both time-consuming and labor-intensive. In this article, we propose to select and subsequently classify images into categories and subcategories. Specifically, we first obtain a list of candidate subcategory labels from untagged corpora. Then, we purify these subcategory labels through calculating the relevance to the target category. To suppress the search error and noisy subcategory label-induced outlier images, we formulate outlier images removing and the optimal classification models learning as a unified problem to jointly learn multiple classifiers, where the classifier for a category is obtained by combining multiple subcategory classifiers. Compared with the existing subcategorization works, our approach eliminates the dependence on expert knowledge and labeled images. Extensive experiments on image categorization and subcategorization demonstrate the superiority of our proposed approach.

Exploiting Web Images for Multi-Output Classification: From Category to Subcategories