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arXiv 2408.03433cs.CVcs.LG

混合扩散模型:结合监督与生成式预训练以实现分割模型的标签高效微调

Hybrid diffusion models: combining supervised and generative pretraining for label-efficient fine-tuning of segmentation models

Mines Paris(巴黎矿业学院);PSL University(巴黎文理研究大学);EPFL(洛桑联邦理工学院);Swiss Data Science Center(瑞士数据科学中心)

Bruno Sauvalle, Mathieu Salzmann

AI总结:

本文提出一种混合预训练方法,通过同时进行图像去噪和掩码预测的代理任务,融合监督与生成式预训练,在多个数据集上验证其能提升分割模型在少样本领域的标签高效微调性能。

摘要:

本文研究分割模型的标签高效微调任务:假设在一个领域中有大规模标注数据集,可以训练出准确的分割模型,而我们需要在只有少量样本的相关领域上对该模型进行适配。我们观察到这种适配可以通过两种不同的方法完成:第一种方法是监督预训练,即直接采用在第一个领域上通过经典监督学习训练得到的模型,并利用第二个领域中可用的标注样本对其进行微调。第二种方法是在第一个领域上使用通用的代理任务进行自监督预训练,以获得高质量的表征,然后利用这些表征以标签高效的方式在第二个领域上训练模型。本文提出通过引入一种新的代理任务来融合这两种方法,该任务是在第一个领域上同时执行图像去噪和掩码预测。我们论证这一选择的动机是:基于扩散模型理论,以噪声水平为条件的图像去噪器可以被视为未标注图像分布的生成模型;同理,在假设从图像到分割掩码的映射是确定性的前提下,使用这一新代理任务训练的模型可以被视为图像与分割掩码联合分布的生成模型。随后,我们在多个数据集上通过实验证明,与仅使用监督预训练或仅使用无监督预训练得到的相似模型相比,对使用该方法预训练的模型进行微调能够取得更好的结果。

英文摘要:

We are considering in this paper the task of label-efficient fine-tuning of segmentation models: We assume that a large labeled dataset is available and allows to train an accurate segmentation model in one domain, and that we have to adapt this model on a related domain where only a few samples are available. We observe that this adaptation can be done using two distinct methods: The first method, supervised pretraining, is simply to take the model trained on the first domain using classical supervised learning, and fine-tune it on the second domain with the available labeled samples. The second method is to perform self-supervised pretraining on the first domain using a generic pretext task in order to get high-quality representations which can then be used to train a model on the second domain in a label-efficient way. We propose in this paper to fuse these two approaches by introducing a new pretext task, which is to perform simultaneously image denoising and mask prediction on the first domain. We motivate this choice by showing that in the same way that an image denoiser conditioned on the noise level can be considered as a generative model for the unlabeled image distribution using the theory of diffusion models, a model trained using this new pretext task can be considered as a generative model for the joint distribution of images and segmentation masks under the assumption that the mapping from images to segmentation masks is deterministic. We then empirically show on several datasets that fine-tuning a model pretrained using this approach leads to better results than fine-tuning a similar model trained using either supervised or unsupervised pretraining only.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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