EchoSR: Efficient Context Harnessing for Lightweight Image Super-Resolution

TL;DR

EchoSR introduces an efficient framework for lightweight image super-resolution that unifies multi-scale receptive field modeling and hierarchical context fusion, achieving superior performance and faster speed.

Contribution

It proposes a novel context-harnessing strategy that decouples feature learning into local, multi-scale, and global stages, enhancing efficiency and scalability.

Findings

Outperforms state-of-the-art lightweight SR methods on multiple benchmarks.

Achieves approximately 2x faster processing speed.

Demonstrates effective multi-scale and hierarchical context integration.

Abstract

Image super-resolution (SR) aims to reconstruct high-quality, high-resolution (HR) images from low-resolution (LR) inputs and plays a critical role in various downstream applications. Despite recent advancements, balancing reconstruction fidelity and computational efficiency remains a fundamental challenge, particularly in resource-constrained scenarios. While existing lightweight methods attempt to expand receptive fields, many of them either incur substantial computational overhead, naively scale up kernel sizes, or lack mechanisms for coherent multi-scale integration, limiting their overall effectiveness and scalability. To address these limitations, we propose EchoSR, an efficient context-harnessing framework for lightweight image super-resolution, which unifies multi-scale receptive field modeling and hierarchical context fusion. EchoSR decouples feature learning into disentangled local, multi-scale, and global modeling stages through an efficient context-harnessing strategy, and further promotes seamless cross-scale integration via a cross-scale overlapping fusion mechanism. Extensive experiments have shown that EchoSR consistently outperforms state-of-the-art lightweight super-resolution methods across multiple benchmarks, while also achieving a faster speed $(\sim 2\times)$. The source code is available at https://github.com/funnyWang-Echoes/EchoSR.