[Pytorch] Faster SRCNN

Implementation of FSRCNN model in Accelerating the Super-Resolution Convolutional Neural Network paper with Pytorch.

Tensorflow version: https://github.com/Nhat-Thanh/FSRCNN-TF

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

I implemented 3 models, FSRCNN-x2, FSRCNN-x3, FSRCNN-x4.

Contents

• Train
• Test
• Demo
• Evaluate
• References

Train

You run this command to begin the training:

python train.py  --steps=300000             \
                 --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 300000 steps:

You can get the models here:

• FSRCNN-x2.pt
• FSRCNN-x3.pt
• FSRCNN-x4.pt

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}/FSRCNN-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/test1.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. I use Set5's Butterfly to show my result:

Model	Set5	Set14	BSD100	Urban100
FSRCNN-x2	38.7593	34.5086	34.4503	31.6858
FSRCNN-x3	34.5420	31.2409	31.2723	X
FSRCNN-x4	31.9589	29.3272	29.6845	27.0038

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

References

• Accelerating the Super-Resolution Convolutional Neural Network: https://arxiv.org/abs/1608.00367
• 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