[Tensorflow] Real-Time Super-Resolution

Implementation of ESPCN model in Real-Time Single Image and Video Super-Resolution Using an Efficient Sub-Pixel Convolutional Neural Network paper with Tensorflow 2x.

Pytorch version: https://github.com/Nhat-Thanh/ESPCN-Pytorch

I used Adam with optimize tuned hyperparameters instead of SGD + Momentum.

I implemented 3 models in the paper, ESPCN-x2, ESPCN-x3, ESPCN-x4

Contents

• Train
• Test
• Demo
• Evaluate
• References

Train

You run this command to begin the training:

python train.py  --steps=200000             \
                 --scale=2                  \
                 --batch_size=128           \
                 --save-best-only=0         \
                 --save-every=1000          \
                 --save-log=0               \
                 --ckpt-dir="checkpoint/x2" 

• --save-best-only: if it's equal to 0, model weights will be saved every save-every steps.
• --save-log: if it's equal to 1, train loss, train metric, validation loss, validation metric will be saved every save-every steps.

NOTE: if you want to re-train a new model, you should delete all files in sub-directories in checkpoint directory. Your checkpoint will be saved when above command finishs and can be used for the next times, so you can train a model on Google Colab without taking care of GPU time limit.

I trained 3 models on Google Colab in 200000 steps:

You can get the models here

• ESPCN-x2.h5
• ESPCN-x3.h5
• ESPCN-x4.h5

Test

I use Set5 as the test set. After Training, you can test models with scale factors x2, x3, x4, the result is calculated by compute average PSNR of all images.

python test.py --scale=2 --ckpt-path="default"

• --ckpt-path="default" means you are using default model path, aka checkpoint/x{scale}/ESPCN-x{scale}.h5. If you want to use your trained model, you can pass yours to --ckpt-path.

Demo

After Training, you can test models with this command, the result is the sr.png.

python demo.py --image-path="dataset/test2.png" \
               --ckpt-path="default"            \
               --scale=2

• --ckpt-path is the same as in Test

Evaluate

I evaluated models with Set5, Set14, BSD100 and Urban100 dataset by PSNR:

Model	Set5	Set14	BSD100	Urban100
ESPCN-x2	34.5470	33.1083	32.9382	30.7794
ESPCN-x3	34.6995	31.3241	31.3362	X
ESPCN-x4	32.1087	29.4295	29.7396	27.0997

Bicubic x2-x3-x4 (top), ESPCN x2-x3-x4 (bottom).

Bicubic x2-x3-x4 (top), ESPCN x2-x3-x4 (bottom).

Source: game ZingSpeed Mobile

References

• Real-Time Single Image and Video Super-Resolution Using an Efficient Sub-Pixel Convolutional Neural Network: https://arxiv.org/abs/1609.05158
• T91, General100: http://vllab.ucmerced.edu/wlai24/LapSRN/results/SR_training_datasets.zip
• Set5: https://filebox.ece.vt.edu/~jbhuang/project/selfexsr/Set5_SR.zip
• Set14: https://filebox.ece.vt.edu/~jbhuang/project/selfexsr/Set14_SR.zip
• BSD100: https://filebox.ece.vt.edu/~jbhuang/project/selfexsr/BSD100_SR.zip
• Urban100: https://filebox.ece.vt.edu/~jbhuang/project/selfexsr/Urban100_SR.zip