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arXiv 2502.02483cs.LGstat.ML
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基于评分规则的分布扩散模型

Distributional Diffusion Models with Scoring Rules

Google DeepMind(谷歌DeepMind)

Valentin De Bortoli, Alexandre Galashov, J. Swaroop Guntupalli, Guangyao Zhou, Kevin Murphy, Arthur Gretton, Arnaud Doucet

AI总结:

本文提出用评分规则学习干净数据在噪声条件下的后验分布,替代仅估计条件均值的回归损失,从而在粗时间尺度上采样逆向过程,显著加速扩散模型推理,并在图像和机器人轨迹生成中验证了其优势。

摘要:

扩散模型能够生成高质量的合成数据。其运作方式是定义一个连续时间的前向过程,该过程逐步向数据添加高斯噪声,直至数据被完全破坏。相应的逆向过程则逐步将高斯样本“去噪”为来自数据分布的样本。然而,生成高质量输出需要许多离散化步骤,以获得对逆向过程的忠实近似。这一过程代价高昂,并推动了众多加速方法的发展。我们提出通过学习干净数据样本在给定其噪声版本条件下的后验分布来实现样本生成,而不仅仅是学习该分布的均值。这使我们能够在较粗的时间尺度上从逆向过程的概率转移中采样,从而显著加速推理,同时将输出质量的退化降至最低。这一目标通过用评分规则替换用于估计条件均值的标准回归损失来实现。我们在图像生成和机器人轨迹生成上验证了我们的方法,在少量离散化步骤下,我们始终优于标准扩散模型。

英文摘要:

Diffusion models generate high-quality synthetic data. They operate by defining a continuous-time forward process which gradually adds Gaussian noise to data until fully corrupted. The corresponding reverse process progressively "denoises" a Gaussian sample into a sample from the data distribution. However, generating high-quality outputs requires many discretization steps to obtain a faithful approximation of the reverse process. This is expensive and has motivated the development of many acceleration methods. We propose to accomplish sample generation by learning the posterior {\em distribution} of clean data samples given their noisy versions, instead of only the mean of this distribution. This allows us to sample from the probability transitions of the reverse process on a coarse time scale, significantly accelerating inference with minimal degradation of the quality of the output. This is accomplished by replacing the standard regression loss used to estimate conditional means with a scoring rule. We validate our method on image and robot trajectory generation, where we consistently outperform standard diffusion models at few discretization steps.

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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