INSTRE

Abstract

Over the last several decades, researches on visual object retrieval and recognition have achieved fast and remarkable success. However, while the category-level tasks prevail in the community, the instance-level tasks (especially recognition) have not yet received adequate focuses. Applications such as content-based search engine and robot vision systems have alerted the awareness to bring instance-level tasks into a more realistic and challenging scenario. Motivated by the limited scope of existing instance-level datasets, in this article we propose a new benchmark for INSTance-level visual object REtrieval and REcognition (INSTRE). Compared with existing datasets, INSTRE has the following major properties: (1) balanced data scale, (2) more diverse intraclass instance variations, (3) cluttered and less contextual backgrounds, (4) object localization annotation for each image, (5) well-manipulated double-labelled images for measuring multiple object (within one image) case. We will quantify and visualize the merits of INSTRE data, and extensively compare them against existing datasets. Then on INSTRE, we comprehensively evaluate several popular algorithms to large-scale object retrieval problem with multiple evaluation metrics. Experimental results show that all the methods suffer a performance drop on INSTRE, proving that this field still remains a challenging problem. Finally we integrate these algorithms into a simple yet efficient scheme for recognition and compare it with classification-based methods. Importantly, we introduce the realistic multiobjects recognition problem. All experiments are conducted in both single object case and multiple objects case.