Summary
The paper deals with web-scale visual entity recognition, which consists of math a question(text)-image query to one of the 6M entities (wikipedia page title) of a base of reference. In the vein of previous works, the task is addressed with a generative text-to-image model, the challenge lying in building the training dataset of this model and the method to learn it (task/losses considered). The approach is based on the recently published dataset Entity-Web-LI which associates an entity (name) to the images of an image-caption dataset. The novelty lies in an additional module of curation that relies on a multimodal LLM (Gemini), which asserts the relevance of the image retrieved in the image-caption external dataset. The multimodal LLM is also asked to provide explanations on its curation. With the novel training dataset, a Git-Large model is trained and evaluated in the context of visual entity recognition (OVEN benchmark) and zero-shot fine-grained classification (5 benchmarks) with better performances than the recent paper the work is built. The work is completed by several experiments of analysis and ablation.
Strengths
* the proposed approach is built upon a method [6] recently published at CVPR 2024, that is after the NeurIPS 2024 submission deadline. All the experimental evaluations are compared to this paper with a similar model (GIT-Large). They also report the results that [6] obtained with another model (GER-ALD) that has a similar complexity (400M parameters) but obtained better results that Git-Large on the task of large-scale entity recognition. In all cases, the proposed model has better performance.
* the approach is evaluated on both the task of large-scale entity recognition (OVEN query and OVEN entity) and on five benchmarks of fine-grained classification in a zero-shot setting, with better performances than [6] in all cases, according to all metrics. It is worth noting that the experimental results on (zero-shot) fine-grained classification are new ([6] did not report such results) and that much more metrics/settings are reported in this paper than in [6] on OVEN. The authors also report experiments of visual matching with CLIP and Dinov2 on six benchmarks, showing that the proposed dataset allows a significant boost in performance.
* the analyses and ablation in Section 4.3 are quite detailed and give a fair view of the contribution of each method component as well as its behavior in "degraded mode". In particular, using their smaller dataset, the authors report results using LAION
Weaknesses
* It is regrettable to rely on a private model (Gemini-pro) to build the main contribution of the paper, which is the training dataset. There's no guarantee that this model will be stable over time, such that the proposed method (to build the dataset) may not be reproducible in a couple of months. This issue would nevertheless be partially mitigated if the dataset itself is released, although it still limits the interest of the method itself (e.g maybe another prompt would be required to get comparable results, or another multi-task learning to train the T2I model...). Surprisingly, this aspect is not addressed in the "Limitations" of Section 5.
* The authors argue (lines 239-243) that "the zero-shot performance of the multimodal LLM on OVEN" is much lower than those obtained when it is used alone thus it "suggest[s] that we are not merely distilling from the considered multimodal LLM". However, it is hard to believe that the gain in performances over [6] is not essentially due to the use of an additive (large, complex and trained on many data) LLM. Beyond the fact the namely LLM is opaque (see above) the contribution seems to mainly consist of a RAG-like approach to filter and correct the entities associated with the images by [6], relying on a black box which makes the process difficult to actually understand. So yes, "it works", but the scientific contribution nevertheless seems limited in that sense.
**minor**
* line 543 "if you answer" --> "if your answer"
* in Appendix A.5, the authors report that the mapping used for fine-grained classification was that proposed by OVEN "then improved it through a careful manual review". For the sake of reproducibility, it should be clear that this mapping will be released to the community.
Questions
* Can we have an idea of the additional computational complexity (and resource usage) due to Gemini?
* In the same vein, is it possible to estimate the performance boost/drop with another external "multimodal LLM"?
* The authors report that the code is not released (Checklist "Experimental Result Reproducibility") but do they at least plan to release the new "mapping" manually curated and used for fine-grained classification?
Limitations
Lines 324-332 are specifically dedicated to the limitations of the approach. It highlights the dependence of the approach on the availability of relevant external knowledge (that is Wikipedia in the context of the paper) as well as the fact that the proposed approach is expensive in terms of computations. One can regret that the message is vague and generic, without specific insight into the actual proposed method, not to mention possible quantitative hints on the actual computational time (of complexity in terms of memory). It refers to Appendix A.2 but that last focuses again on the performance of the model. However, Appendix A.3.3 reports the usage of 256 TPUv3 during 15+44 hours for the models used in the paper. This only concerns the training of the GitLarge models, but an estimation of the additive resources used to build the dataset (that is the main novelty of the paper) with Gemini would also be relevant.