Publication Type
Conference Proceeding Article
Version
publishedVersion
Publication Date
10-2019
Abstract
This paper tackles a rarely explored but critical problem within learning to hash, i.e., to learn hash codes that effectively discriminate hard similar and dissimilar examples, to empower large-scale image retrieval. Hard similar examples refer to image pairs from the same semantic class that demonstrate some shared appearance but have different fine-grained appearance. Hard dissimilar examples are image pairs that come from different semantic classes but exhibit similar appearance. These hard examples generally have a small distance due to the shared appearance. Therefore, effective encoding of the hard examples can well discriminate the relevant images within a small Hamming distance, enabling more accurate retrieval in the top-ranked returned images. However, most existing hashing methods cannot capture this key information as their optimization is dominated by easy examples, i.e., distant similar/dissimilar pairs that share no or limited appearance. To address this problem, we introduce a novel Gamma distribution-enabled and symmetric Kullback-Leibler divergence-based loss, which is dubbed dual hinge loss because it works similarly as imposing two smoothed hinge losses on the respective similar and dissimilar pairs. Specifically, the loss enforces exponentially variant penalization on the hard similar (dissimilar) examples to emphasize and learn their fine-grained difference. It meanwhile imposes a bounding penalization on easy similar (dissimilar) examples to prevent the dominance of the easy examples in the optimization while preserving the high-level similarity (dissimilarity). This enables our model to well encode the key information carried by both easy and hard examples. Extensive empirical results on three widely-used image retrieval datasets show that (i) our method consistently and substantially outperforms state-of-the-art competing methods using hash codes of the same length and (ii) our method can use significantly (e.g., 50%-75%) shorter hash codes to perform substantially better than, or comparably well to, the competing methods.
Keywords
Image Retrieval, Deep Hashing, Hard Examples, Hinge Loss
Discipline
Databases and Information Systems | Data Storage Systems
Research Areas
Data Science and Engineering
Publication
Proceedings of the 27th ACM International Conference on Multimedia, Nice, France, 2019 October 21-25
First Page
1535
Last Page
1542
Identifier
10.1145/3343031.3350927
Publisher
ACM
City or Country
Nice, France
Citation
YAN, Cheng; PANG, Guansong; BAI, Xiao; SHEN, Chunhua; ZHOU, Jun; and HANCOCK, Edwin.
Deep hashing by discriminating hard examples. (2019). Proceedings of the 27th ACM International Conference on Multimedia, Nice, France, 2019 October 21-25. 1535-1542.
Available at: https://ink.library.smu.edu.sg/sis_research/7139
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.