Optimal Denoising in Score-Based Generative Models: The Role of Data Regularity
- URL: http://arxiv.org/abs/2503.12966v1
- Date: Mon, 17 Mar 2025 09:22:14 GMT
- Title: Optimal Denoising in Score-Based Generative Models: The Role of Data Regularity
- Authors: Eliot Beyler, Francis Bach,
- Abstract summary: We show that half-denoising is better than full-denoising for regular enough densities.<n>We prove that full-denoising can alleviate the curse of dimensionality under a linear manifold hypothesis.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: Score-based generative models achieve state-of-the-art sampling performance by denoising a distribution perturbed by Gaussian noise. In this paper, we focus on a single deterministic denoising step, and compare the optimal denoiser for the quadratic loss, we name ''full-denoising'', to the alternative ''half-denoising'' introduced by Hyv{\"a}rinen (2024). We show that looking at the performances in term of distance between distribution tells a more nuanced story, with different assumptions on the data leading to very different conclusions.We prove that half-denoising is better than full-denoising for regular enough densities, while full-denoising is better for singular densities such as mixtures of Dirac measures or densities supported on a low-dimensional subspace. In the latter case, we prove that full-denoising can alleviate the curse of dimensionality under a linear manifold hypothesis.
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