ILIAS: Instance-Level Image retrieval At Scale
Authors: name: Giorgos Kordopatis-Zilos; name: Vladan Stojnić; name: Anna Manko; name: Pavel Šuma; name: Nikolaos-Antonios Ypsilantis; name: Nikos Efthymiadis; name: Zakaria Laskar; name: Jiří Matas; name: Ondřej Chum; name: Giorgos Tolias
Published: 2025-02-17 12:42:38

Abstract: This work introduces ILIAS, a new test dataset for Instance-Level Image
retrieval At Scale. It is designed to evaluate the ability of current and
future foundation models and retrieval techniques to recognize particular
objects. The key benefits over existing datasets include large scale, domain
diversity, accurate ground truth, and a performance that is far from saturated.
ILIAS includes query and positive images for 1,000 object instances, manually
collected to capture challenging conditions and diverse domains. Large-scale
retrieval is conducted against 100 million distractor images from YFCC100M. To
avoid false negatives without extra annotation effort, we include only query
objects confirmed to have emerged after 2014, i.e. the compilation date of
YFCC100M. An extensive benchmarking is performed with the following
observations: i) models fine-tuned on specific domains, such as landmarks or
products, excel in that domain but fail on ILIAS ii) learning a linear
adaptation layer using multi-domain class supervision results in performance
improvements, especially for vision-language models iii) local descriptors in
retrieval re-ranking are still a key ingredient, especially in the presence of
severe background clutter iv) the text-to-image performance of the
vision-language foundation models is surprisingly close to the corresponding
image-to-image case. website: https://vrg.fel.cvut.cz/ilias/