I-Diff: Structural Regularization for High-Fidelity Diffusion Models

Abstract

Denoising Diffusion Probabilistic Models (DDPMs) have significantly advanced generative AI, achieving impressive results in high-quality image and data generation. However, enhancing fidelity without compromising semantic content remains a key challenge in the field. Recent diffusion research in multiple disciplines has introduced objectives and architectural refinements that tighten the match between generated and real data distributions, yielding higher fidelity than earlier generative frameworks. Multi-stage architectures, physics-guided modeling, semantic conditioning, and rarity-aware generation are some of the explored works to achieve this task. However, the integration of structural information of the data distribution into DDPM has largely been unexplored. The conventional DDPM framework relies solely on the $L^2$ norm between the additive and predicted noise to generate new data distributions. We introduce I-Diff, an improved version of DDPM that incorporates a carefully designed regularizer, effectively enabling the model to encode structural information, thereby preserving the inherent fidelity of the data distribution. The proposed approach is validated through extensive experiments on DDPM, Improved DDPM and Latent Diffusion Model across multiple datasets. Empirical results demonstrate significant improvements in fidelity (Density and Precision increase 10% and 37% in CIFAR-100 dataset respectively) across other tested datasets. These results highlight the effectiveness of our method in enhancing the fidelity of the generated data. Notably, improvements across different models highlight the model-agnostic nature of our proposed method in the wider field of generative AI.