DiffusionRIR: Room Impulse Response Interpolation using Diffusion Models
Sagi Della Torre, Mirco Pezzoli, Fabio Antonacci, Sharon Gannot
TL;DR
The paper addresses the challenge of reconstructing high-resolution Room Impulse Responses (RIRs) from sparse measurements by casting the RIR set as a 2D image and applying a diffusion-model inpainting approach. It introduces a RePaint-style DDPM framework trained on a small RIR dataset and demonstrates reconstruction of missing RIRs for linear and curved microphone arrays, outperforming spline cubic interpolation in NMSE and Cosine Distance. The method maintains robustness to large gaps and shows promising generalization across array geometries and room configurations, with analyses of EDC-derived $T_{60}$ and source-angle effects. This diffusion-based approach offers a data-efficient pathway to high-resolution acoustic mapping and can enable data augmentation and improved sound-field tasks with limited measurements.
Abstract
Room Impulse Responses (RIRs) characterize acoustic environments and are crucial in multiple audio signal processing tasks. High-quality RIR estimates drive applications such as virtual microphones, sound source localization, augmented reality, and data augmentation. However, obtaining RIR measurements with high spatial resolution is resource-intensive, making it impractical for large spaces or when dense sampling is required. This research addresses the challenge of estimating RIRs at unmeasured locations within a room using Denoising Diffusion Probabilistic Models (DDPM). Our method leverages the analogy between RIR matrices and image inpainting, transforming RIR data into a format suitable for diffusion-based reconstruction. Using simulated RIR data based on the image method, we demonstrate our approach's effectiveness on microphone arrays of different curvatures, from linear to semi-circular. Our method successfully reconstructs missing RIRs, even in large gaps between microphones. Under these conditions, it achieves accurate reconstruction, significantly outperforming baseline Spline Cubic Interpolation in terms of Normalized Mean Square Error and Cosine Distance between actual and interpolated RIRs. This research highlights the potential of using generative models for effective RIR interpolation, paving the way for generating additional data from limited real-world measurements.
