Abstract
Multi-modal crowd counting involves estimating crowd density from both visual and thermal/depth images. This task is challenging due to the significant gap between these distinct modalities. In this paper, we propose a novel approach by introducing an auxiliary broker modality and on this basis frame the task as a triple-modal learning problem. We devise a fusion-based method to generate this broker modality, leveraging a non-diffusion, lightweight counterpart of modern denoising diffusion-based fusion models. Additionally, we identify and address the ghosting effect caused by direct cross-modal image fusion in multi-modal crowd counting. Through extensive experimental evaluations on popular multi-modal crowd counting datasets, we demonstrate the effectiveness of our method, which introduces only 4 million additional parameters, yet achieves promising results. The code is available at https://github.com/HenryCilence/Broker-Modality-Crowd-Counting.
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Notes
- 1.
For the infrared-visible fusion task, the DDFM model retains both structural and detailed information from the source images, meeting the visual fidelity requirements as well. Thus it is used to pre-train our broker modal generator based on its favorable multi-modal fusion results.
- 2.
To better illustrate the challenges posed by this problem, we conducted experiments to assess the effectiveness of image alignment-based de-ghosting algorithms such as [4, 9, 30]. Our results indicate that while satisfactory outcomes can be attained with natural image pairs, the de-ghosting algorithm performs inadequately on image pairs with low imaging quality, such as the data used in this study. Further comprehensive experiments are available in the supplementary material.
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Acknolwedgement
This work was funded in part by the National Natural Science Foundation of China (62076195, 62376070) and in part by the Fundamental Research Funds for the Central Universities (AUGA5710011522).
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Meng, H., Hong, X., Wang, C., Shang, M., Zuo, W. (2025). Multi-modal Crowd Counting via a Broker Modality. In: Leonardis, A., Ricci, E., Roth, S., Russakovsky, O., Sattler, T., Varol, G. (eds) Computer Vision – ECCV 2024. ECCV 2024. Lecture Notes in Computer Science, vol 15132. Springer, Cham. https://doi.org/10.1007/978-3-031-72904-1_14
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