Alleviating Distortion in Image Generation via Multi-Resolution
  Diffusion Models
Authors: name: Qihao Liu, name: Zhanpeng Zeng, name: Ju He, name: Qihang Yu, name: Xiaohui Shen, name: Liang-Chieh Chen

This paper presents innovative enhancements to diffusion models by
integrating a novel multi-resolution network and time-dependent layer
normalization. Diffusion models have gained prominence for their effectiveness
in high-fidelity image generation. While conventional approaches rely on
convolutional U-Net architectures, recent Transformer-based designs have
demonstrated superior performance and scalability. However, Transformer
architectures, which tokenize input data (via "patchification"), face a
trade-off between visual fidelity and computational complexity due to the
quadratic nature of self-attention operations concerning token length. While
larger patch sizes enable attention computation efficiency, they struggle to
capture fine-grained visual details, leading to image distortions. To address
this challenge, we propose augmenting the Diffusion model with the
Multi-Resolution network (DiMR), a framework that refines features across
multiple resolutions, progressively enhancing detail from low to high
resolution. Additionally, we introduce Time-Dependent Layer Normalization
(TD-LN), a parameter-efficient approach that incorporates time-dependent
parameters into layer normalization to inject time information and achieve
superior performance. Our method's efficacy is demonstrated on the
class-conditional ImageNet generation benchmark, where DiMR-XL variants
outperform prior diffusion models, setting new state-of-the-art FID scores of
1.70 on ImageNet 256 x 256 and 2.89 on ImageNet 512 x 512. Project page:
https://qihao067.github.io/projects/DiMR