Are visual dictionaries generalizable?

Otavio A. B. Penatti; Eduardo Valle; Ricardo da S. Torres

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arXiv · 1205.2663

Are visual dictionaries generalizable?

Otavio A. B. Penatti·Eduardo Valle·Ricardo da S. Torres

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Abstract

Mid-level features based on visual dictionaries are today a cornerstone of systems for classification and retrieval of images. Those state-of-the-art representations depend crucially on the choice of a codebook (visual dictionary), which is usually derived from the dataset. In general-purpose, dynamic image collections (e.g., the Web), one cannot have the entire collection in order to extract a representative dictionary. However, based on the hypothesis that the dictionary reflects only the diversity of low-level appearances and does not capture semantics, we argue that a dictionary based on a small subset of the data, or even on an entirely different dataset, is able to produce a good representation, provided that the chosen images span a diverse enough portion of the low-level feature space. Our experiments confirm that hypothesis, opening the opportunity to greatly alleviate the burden in generating the codebook, and confirming the feasibility of employing visual dictionaries in large-scale dynamic environments.

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Otavio A. B. Penatti, Eduardo Valle, Ricardo da S. Torres. 2012-05-11. Are visual dictionaries generalizable?. https://arxiv.org/abs/1205.2663

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