RefQSR: Reference-based Quantization for Image
Super-Resolution Networks
Hongjae Lee*,
Jun-Sang Yoo,
Seung-Won Jung,
Korea University
Corresponding author
Examples of patch-wise bit selections of (b) CADyQ and (c) CADyQ-RefQSR for the SRResNet baseline, where the darker the patches, the higher the average bit precision. Note that CADyQ allocates higher bit precision to many patches with textual details, whereas CADyQ-RefQSR utilizes image self-similarity to prevent assigning high-bit precision to similar patches.


Abstract

Single image super-resolution (SISR) aims to reconstruct a high-resolution image from its low-resolution observation. Recent deep learning-based SISR models show high performance at the expense of increased computational costs, limiting their use in resource-constrained environments. As a promising solution for computationally efficient network design, network quantization has been extensively studied. However, existing quantization methods developed for SISR have yet to effectively exploit image self-similarity, which is a new direction for exploration in this study. We introduce a novel method called reference-based quantization for image super-resolution (RefQSR) that applies high-bit quantization to several representative patches and uses them as references for low-bit quantization of the rest of the patches in an image. To this end, we design dedicated patch clustering and reference-based quantization modules and integrate them into existing SISR network quantization methods. The experimental results demonstrate the effectiveness of RefQSR on various SISR networks and quantization methods.

Qualitative Results on Urban100

We provide more visual results. Click on the thumbnail to see for yourself.

Move your mouse over the first image to zoom

GT

CADyQ (δbit)

CADyQ-RefQSR (δ-3bit)


Qualitative Results on Test2k

We provide more visual results. Click on the thumbnail to see for yourself.

Move your mouse over the first image to zoom

GT

CADyQ (δbit)

CADyQ-RefQSR (δ-3bit)


Additional Qualitative Results

Visual comparison of DDTB and DDTB-RefQSR on SRResNet for scale factor of 2.

Quantitative Results

Quantitative comparisons of various quantization methods on SRResNet for scale factor of 2.

Acknowledgements

This template was originally made by Phillip Isola and Richard Zhang for a colorful ECCV project; the code can be found here.