A semantics and image retrieval system for hierarchical image databases

• Proposes automatic semantics and image retrieval system for hierarchical databases.
• System uses < 1/3 search space to retrieve semantics, and finally similar images.
• ≈ 77% semantic retrieval accuracy on ImageNet. Uses ≈ 4% space to retrieve images.
• System reports precision of 0.78 @ 20 and 0.67 @ 100 images on categorized WANG.
• The study explores adequacy of visual signatures set used to represent a semantic.

This work presents a content based semantics and image retrieval system for semantically categorized hierarchical image databases. Each module is designed with an aim to develop a system that works closer to human perception. Images are mapped to a multidimensional feature space, where images belonging a semantic are clustered and indexed to acquire its efficient representation. This helps in handling the existing variability or heterogeneity within this semantic. Adaptive combinations of the obtained depictions are utilized by the branch selection and pruning algorithms to identify some closer semantics and select only a part of the large hierarchical search space for actual search. So obtained search space is finally used to retrieve desired semantics and similar images corresponding to them. The system is evaluated in terms of accuracy of the retrieved semantics and precision-recall curves. Experiments show promising semantics and image retrieval results on hierarchical image databases. The results reported with non-hierarchical but categorized image databases further prove the efficacy of the proposed system.