TinySR: Pruning Diffusion for Real-World Image Super-Resolution

TL;DR

TinySR is a compact diffusion model designed for real-time, high-quality image super-resolution, reducing computational cost and model size significantly while maintaining perceptual quality.

Contribution

The paper introduces TinySR, a novel lightweight diffusion model with innovative pruning and compression strategies for efficient real-world image super-resolution.

Findings

Achieves up to 5.68x speedup over TSD-SR

Reduces model parameters by 83%

Maintains high perceptual quality in super-resolution

Abstract

Real-world image super-resolution (Real-ISR) focuses on recovering high-quality images from low-resolution inputs that suffer from complex degradations like noise, blur, and compression. Recently, diffusion models (DMs) have shown great potential in this area by leveraging strong generative priors to restore fine details. However, their iterative denoising process incurs high computational overhead, posing challenges for real-time applications. Although one-step distillation methods, such as OSEDiff and TSD-SR, offer faster inference, they remain fundamentally constrained by their large, over-parameterized model architectures. In this work, we present TinySR, a compact yet effective diffusion model specifically designed for Real-ISR that achieves real-time performance while maintaining perceptual quality. We introduce a Dynamic Inter-block Activation and an Expansion-Corrosion Strategy to facilitate more effective decision-making in depth pruning. We achieve VAE compression through channel pruning, attention removal and lightweight SepConv. We eliminate time- and prompt-related modules and perform pre-caching techniques to further speed up the model. TinySR significantly reduces computational cost and model size, achieving up to 5.68x speedup and 83% parameter reduction compared to its teacher TSD-SR, while still providing high quality results.