Summary
the focus of the paper is to improve the model's understanding capability in terms of Commonalities and Differences (CaD) over two images. to address the problem, the paper proposes a two-stage approach, in which the first stage utilizes LLM to generate the CaD information based on the caption only from the Localized Narratives dataset and then train a model. the second stage applies the trained model to generate more training data. a QA dataset is created to further diversity and enhance the data source.
Strengths
this paper introduces CaD-VI, a two-phase approach for enhancing visual instruction tuning in large multimodal models (LMMs) with a specific focus on comparing commonalities and differences (CaD) between image pairs. this work addresses an underexplored area in LMMs and providing valuable insights for visual reasoning.
the paper contributes a dataset CaD-Inst containing 349K image pairs for CaD instruction tuning, and CaD-QA, a benchmark of 7.5K open-ended questions designed to evaluate CaD capabilities. These resources are likely to foster advancements in LMM training and evaluation.
Weaknesses
the paper uses the open-sourced LLM or MLLM to generate the training data. what if using the GPT-4 model to generate data directly from the image, rather than from the image descriptions? one less-costly approach could be just to test, say, 5 data points, and see how the gap is, although a more comprehensive way is to replace the open-sourced component with, e.g. gpt-4 in the proposed pipeline. in this way, it may also work to directly use the image rather than the caption to generate the CaD data in the first stage?
in the proposed approach, there are two stages. the first is to generate training data and then do the training on these data. the second is to use the trained model to generate the training data. what if skipping the second phase, but generating more data in the first stage? this sounds like more reasonable and easier, maybe also more effective, way? one reason of why the second stage exists could be to save the cost, as the first stage requires the captioning and LLM to generate data, but this may not be a problem since all components are open-sourced?
in the first stage, the caption is from the dataset itself (this may also be part of the reason why stage 2 exists). what if applying a MLLM to do the captioning? if it also works, it would make the pipeline more scalable to generate even more data.
another question is how the scaling curve looks like with more training data in the first stage. that is, if it is 1k, how the perf is; if it is 10k, how the perf is; if it is 100k, .... the reason i'm more interested in this question is that the paper basically curates some training data and then fine-tune the model on these data to improve the performance on the target domain. this is a quite reasonable approach. the dataset scale here could be one of the main factors that impact the performance.