Benchmarking and Improving Detail Image Caption
Hongyuan Dong, Jiawen Li, Bohong Wu, Jiacong Wang, Yuan Zhang, Haoyuan Guo
TL;DR
This paper tackles the misalignment between state-of-the-art LVLMs and reliable evaluation in detail image captioning. It introduces DetailCaps, a higher-quality, expert-annotated benchmark, and CAPTURE, an element-centric metric that leverages a T5-based parser, stop-word filtering, and a three-stage matching process to align closely with human judgments. It further presents a five-stage detail caption construction pipeline that synthesizes high-quality captions using only the LVLM and open-source tools, with a self-looping option to further boost data quality. Experimental results show CAPTURE achieves the strongest consistency with expert judgments, while the synthesized data pipeline improves LVLMs’ detail captioning and broader understanding across multiple benchmarks, supporting practical benefits for both evaluation and model training.
Abstract
Image captioning has long been regarded as a fundamental task in visual understanding. Recently, however, few large vision-language model (LVLM) research discusses model's image captioning performance because of the outdated short-caption benchmarks and unreliable evaluation metrics. In this work, we propose to benchmark detail image caption task by curating high-quality evaluation datasets annotated by human experts, GPT-4V and Gemini-1.5-Pro. We also design a more reliable caption evaluation metric called CAPTURE (CAPtion evaluation by exTracting and coUpling coRE information). CAPTURE extracts visual elements, e.g., objects, attributes and relations from captions, and then matches these elements through three stages, achieving the highest consistency with expert judgements over other rule-based or model-based caption metrics. The proposed benchmark and metric provide reliable evaluation for LVLM's detailed image captioning ability. Guided by this evaluation, we further explore to unleash LVLM's detail caption capabilities by synthesizing high-quality data through a five-stage data construction pipeline. Our pipeline only uses a given LVLM itself and other open-source tools, without any human or GPT-4V annotation in the loop. Experiments show that the proposed data construction strategy significantly improves model-generated detail caption data quality for LVLMs with leading performance, and the data quality can be further improved in a self-looping paradigm. All code and dataset will be publicly available at https://github.com/foundation-multimodal-models/CAPTURE.
