ABPN (Attention based Back Projection Network for image super-resolution)

By Zhi-Song, Li-Wen Wang and Chu-Tak Li

This repo only provides simple testing codes, pretrained models and the network strategy demo.

We propose a single image super-resolution using Attention based Back Projection Network (ABPN) to achieve good SR performance with low distortion. The paper can be found in arxiv

BibTex

    @InProceedings{Liu2019abpn,
        author = {Liu, Zhi-Song and Wang, Li-Wen and Li, Chu-Tak and Siu, Wan-Chi},
        title = {Image Super-Resolution via Attention based Back Projection Networks},
        booktitle = {IEEE International Conference on Computer Vision Workshop(ICCVW)},
        month = {October},
        year = {2019}
    }

For proposed ABPN model, we claim the following points:

• Attention Back Projection Block to learn cross-correlation of features.

• Refined Back Projection Block to estimate super-resolution residues for better reconstruction.

Dependencies

Python > 3.0
OpenCV library
Pytorch 1.1 
NVIDIA GPU + CUDA
MATLAB 6.0 or above

Complete Architecture

The complete architecture is shown as follows,

Implementation

0. Installation

a. Install conda on your computer. download the code to your local folder.

b. create a conda environemnt by the following command

$ conda create --name ABPN --file requirements.txt

1. Quick testing

---

Copy your image to folder "LR" and run test.sh. The SR images will be in folder "Result"

2. Testing for AIM 2019

---

s1. For AIM2019 Extreme Super-Resolution Challenge - Track 1: Fidelity, run AIM_ensemble_16x.py. Modify the directories of files based on your working environment.

Testing images on AIM2019 Extreme Super-Resolution Challenge - Track 1: Fidelity can be downloaded from the following link:

https://competitions.codalab.org/competitions/20235

s2. For AIM2019 Constrained Super-Resolution Challenge - Track 3: Fidelity optimization, run AIM_ensemble_4x.py. Modify the directories of files based on your working environment.

Testing images on AIM2019 Constrained Super-Resolution Challenge - Track 3: Fidelity optimization can be downloaded from the following link:

https://competitions.codalab.org/competitions/20169

General testing dataset (Set5, Set14, BSD100, Urban100 and Manga109) can be downloaded from:

https://github.com/LimBee/NTIRE2017

3. Training

---

s1. Download the training images from DIV2K and Flickr.

https://data.vision.ee.ethz.ch/cvl/DIV2K/

https://github.com/LimBee/NTIRE2017

s2. Start training on Pytorch

For user who already has installed Pytorch 1.1, simply just run the following code for AIM2019 Constrained Super-Resolution Challenge - Track 3: Fidelity optimization:

$ python main_4x.py

or run the following code for AIM2019 Extreme Super-Resolution Challenge - Track 1: Fidelity:

$ python main_16x.py

---

Experimental results

Validation results on AIM2019 Extreme Super-Resolution Challenge - Track 1: Fidelity can be downloaded from the following link:

https://drive.google.com/open?id=1rMzeN-UmWoCNKoyApEAJ7uSF5ckX34-V

Testing results on AIM2019 Extreme Super-Resolution Challenge - Track 1: Fidelity can be downloaded from the following link:

https://drive.google.com/open?id=1lJFvNKSUxg-pioKqjA39GPqDvvv3ceYj

Validation results on AIM2019 Constrained Super-Resolution Challenge - Track 3: Fidelity optimization can be downloaded from the following link:

https://drive.google.com/open?id=12gCRnI7eUhSrb5F7TN8wm4aWXcP2c6oi

Testing results on AIM2019 Constrained Super-Resolution Challenge - Track 3: Fidelity optimization can be downloaded from the following link:

https://drive.google.com/open?id=1IMSBDtfMxEkn5v6Up3MZ0n-Uk3uN0BBm

Partial image visual comparison

1. Quantitative comparison

We tested on several SR approaches on several datasets for PSNR and SSIM. We have achieve comparable or even better performance.

2. Model complexity

Our proposed ABPN can use 2~3 times less parameters to achieve same PSNR performance!

3. Visualization comparison

Results on 4x image SR on Urban100 dataset